taxonID	type	description	language	source
03DC87FDEC17FFD36FDDF93DA306FFD6.taxon	type_taxon	Type genus. Conchoecia Dana 1849 Composition and main characters. The new tribe consists of 20 genera (Alacia Poulsen, 1973; Boroecia Poulsen, 1973; Conchoecetta Claus, 1890; Conchoecia Dana, 1849; Conchoecilla Claus, 1890; Conchoecissa Claus, 1890; Discoconchoecia Martens, 1979; Gaussicia Poulsen, 1973; Loricoecia Poulsen, 1973; Macroconchoecia Granata and Caporiacco, 1949; Mikroconchoecia Claus, 1890; Mollicia Poulsen, 1973; Obtusoecia Martens, 1979; Orthoc- onchoecia Granata and Caporiacco, 1949; Paraconchoecia Claus, 1890; Paramollicia Poulsen, 1973; Platyconchoecia Poulsen, 1973; Porroecia Martens, 1979; Proceroecia Kock, 1992; Pseudoconchoecia Claus, 1890). All these genera have the LAG opening on the dorsal margin of the left carapace valve posterior to mid-length and usually close to the posterior dorsal corner. The position of the opening of the RAG opens is more variable. In most genera it opens on the margin of the right carapace valve close to the posterior ventral corner. In some of the genera the opening is further forward on the ventral margin; the most extreme example is in Conchoecilla, in which the gland opens just below the rostral incisure. In other genera the gland opening is displaced dorsally up the posterior margin, but never above mid-height (e. g. some species of Paraconchoecia). The genera in this tribe are quite disparate in many of their carapace characters such as size, shape, shoulder vaulting and ornamentation and armature. The PDC is often more angled or even armed with spines on one or both of the carapace valves. The rostra are more elaborate and can be asymmetrical. The external surfaces of the carapace valves vary from being totally smooth to be sculpted shallowly or deeply incised concentric, rectilinear, oblique or polygonal patterns. Other groups of glands may be present along the margins of the carapace valves. In summary: 1. They cover almost the full adult size ranges of halocyprid ostracods from 0.6 to 6.5 mm. 2. The carapace ornamentation ranges from being totally smooth to having faint or deeply incised patterns of longitudinal or concentric lines, or polygonal cells. In a few species armatures of spines line the carapace margins and / or the ridges of the sculpturing, or, in juveniles of one species, the margins of the shoulder vaults. 3. The shoulder vaults can be accentuated, or angled or even winged (e. g. in Alacia) 4. The posterior dorsal corner can be rounded or sharply angled and may be armed with one or more spines on one or both valves. 5. In female the second segment of the first antenna often carries a dorsal seta which is probably homologous to the seta that in males locks around the stem of the frontal organ. 6. The labrum is generally flat or smoothly notched, and is flanked by a double row of numerous, long and curved filaments. 7. The first segment of the endopodite of the maxilla generally has six anterior setae, one lateral seta, and three posterior setae. 8. The toothed edge of the mandibular basale has two peg teeth, which may be spinose or bare. The first of the six triangular cutting teeth is slightly offset from the other five. The inner tooth is broad, and often overlaps more than two of the cutting teeth. 9. The female frontal organ can have a clearly differentiated capitulum in those species that do not have the basal segments of the first antenna fused. 10. In males the c-seta of the first antenna is relatively long (> 10 % carapace length). The a-seta is often S – shaped and inflated at its base, and is simple in all genera except in Mikroconchoecia, in which it is bifid. 11. The hook appendages on the endopodite of each male second antennae are dimorphic, the most extreme example of this dimorphism is seen in Obtusoecia, in which the right hook is very large, whereas the left ‘ hook’ is reduced to a short straight peg.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC16FFDC6FDDF9EDA080FD5A.taxon	type_taxon	Type genus. Metaconchoecia Howe 1955 Synonymy. 1906 a Conchoecia ‘ rotundata ’ group — Müller p. 79 - 86. 1920 Conchoecia ‘ rotundata’ group — Skogsberg, p. 649 – 658. 1949 Metaconchoecia — Granata & Caporiacco p. 5 (nomen nudum). 1955 Metaconchoecia — Howe, p. 118. 1973 Metaconchoecia — Poulsen p. 70. 1978 a Conchoecia — Deevey, p 53 (part). 1980 Conchoecia rotundata group — Deevey & Brooks, p. 85 (part). 1981 Conchoecia ‘ skogsbergi’ species complex — Gooday p. 145. 1986 Metaconchoecia Granata & Caporiacco — Kempf 1986, Index A: 498 (part). 1992 Metaconchoecia — Kock, p. 68. 1995 Metaconchoecia Kock — Kempf 1995, Index A supplement 1, p. 149 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC16FFDC6FDDF9EDA080FD5A.taxon	diagnosis	Diagnosis. Small to medium sized halocyprids (<2 mm). Pelagic in oceanic waters. Carapace cylindrical to globose, tapered anteriorly in some species. The posterior dorsal corner is unarmed, and either smoothly rounded or obtusely angled. Posterior ventral corner is rounded. Carapace lacks sculpture in the majority of species, but when present is either in the form of longitudinal striae or concentric rings. RAG on posterior margin close to posterior end of hinge between carapace valves. LAG on dorsal face usually posterior to rostrum but always anterior to midlength. Labrum with a deep V-shaped cleft. Composition and main characters. The new tribe includes all the species previously attributed to the genus Metaconchoecia, i. e. Müller’s (1906 a, 1912) “ rotundata ” group. Members of this new tribe are distinguished from all other Conchoeciinae genera by the positions of the asymmetrical glands on the carapace valves. The LAG opens on the dorsal margin in the anterior half of the carapace usually just posterior to the anterior end of the hinge between the two carapace valves. In several of the newly designated genera, the LAG opens closer to mid-length, but in one genus, it opens in front of the anterior end of the hinge (i. e. on the rostrum). The RAG opens on the posterior margin, usually close to the posterior end of the hinge and near the rounded posterior dorsal corner of the carapace. However, in some genera the RAG opens lower down the posterior margin sometimes at the apex of a shallow angle. There are often only subtle intergeneric and interspecific differences in the morphologies of the limbs, so confirming the identities of specimens is seldom easy. There may be slight variations in the external appearances of species that clearly have very different ecologies. Preliminary results of barcoding the CO 1 gene of some of these species have confirmed their separate identities (Bucklin et al. 2010). The Metaconchoeciini consists of ten genera, nine of which are newly designated herein. Table 2 compares the previous classification with our revision. In addition to the locations at which the asymmetrical glands open, all the species in the tribe have the following characters in common: 1. They are small in size (≤ 1.9 mm); some are very small (<1 mm). 2. The carapaces are devoid of spines and lack sculpturing in all but two genera, Vityazoecia and Juryoecia (Figs. 3, 5). 3. The shoulder vaults are smooth and are not accentuated. 4. The posterior dorsal ‘ corner’ is either rounded or obtusely angled. 5. In females the second segment of the first antenna lacks a dorsal seta. 6. The labrum is deeply notched and is flanked by relatively short, stubby filaments. 7. There is no seta on basale of the maxilla, and the first segment of the endopodite of the maxilla has four anterior setae, one lateral seta, and three posterior setae (e. g. Fig. 7 F, G). (in Conchoeciini there is a seta on the basale and there are six anterior setae on the first segment of the endopodite) 8. The toothed edge of the mandibular basale has two peg teeth, which are bare and slightly offset from each other, and there are six triangular cutting teeth the first of which is offset from the others. The inner tooth is quite tall and narrow (e. g. Fig. 7 A, B) 9. The female frontal organ is fused into a single unit (e. g. Fig. 9 H), so that the capitulum and shaft are undiffer- entiated. 10. The basal segments of the first antenna of females are fused. 11. In males the c-seta of the first antenna is very short (<6 % carapace length), and the base of the a-seta is usually S – shaped and inflated. In some of the new genera this seta is furnished with one or two side arms (e. g. Fig. 6 B, C) 12. The hook appendages on the endopodites of the male second antennae are relatively small and less dimorphic than in the Conchoeciini.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC16FFDC6FDDF9EDA080FD5A.taxon	distribution	Distribution. This tribe is almost ubiquitous in the World’s oceans. Its species occur at all depths except either in the uppermost 100 m or so at temperate and high latitudes (see Angel et al. 2007), or where dissolved oxygen concentrations are exceptionally low, such as in the North Arabian Sea (unpublished Discovery data; Graves personal communication).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC1FFFC66FDDF8DDA36DFDD1.taxon	description	1890 Conchoecia roduntata — Müller, p. 275. 1894 Conchoecia rotundata — Müller, p. 229. 1906 a Conchoecia rotundata group — Müller, p. 79 (part). 1909 Conchoecia rotundata — Fowler, p 249. 1920 Rotundata group — Skogsberg, p. 648 (part). 1949 Metaconchoecia — Granata & Caporiacco, p. 15 (name unavailable; no type species designated). 1955 Metaconchoecia, Howe, p. 118. 1968 Conchoecia rotundata group — Deevey, p. 50 (part). 1973 Metaconchoecia — Poulsen p. 70 (part) (nomen nudum). 1978 a Conchoecia rotundata Group — Deevey, p. 53 (part). 1980 Conchoecia rotundata group — Deevey & Brooks, p. 85 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 140, 141 (part), 159 (part), 160. 1986 Metaconchoecia Granata & Caporiacco — Kempf, p. 498 (part). 1992 Metaconchoecia — Kock, p. 68. Predated by Howe 1955. 1995 Metaconchoecia Kock — Kempf, p. 149 (part). 1999 Metaconchoecia — Angel Figs 9.58 – 76 (part). 2003 Metaconchoecia — Chavtur, p 2. Nomenclatural issues. The proper authority for this genus has remained a problem for many years. In their original use of the name Granata and Caporiacco (1949) failed to designate a type species, hence technically rendering the generic name unavailable. The next use of the generic name was by Howe (1955) when he drew up a list of ostracod genera for a handbook for geologists. His entry for Metaconchoecia (p. 118) reads as follows: ‘ METACONCHOECIA [Genotype not stated but genus set up for M. macromma, M. pusilla, M. glandulosa, M. kyrtophora, M. nasotuberculata, M. rotundata, M. isocheira, all of which were originally described by G. W. Müller as Conchoecia. Of these M. rotundata is discussed in detail and may be considered as their genotype] Granata and Caporiacco 1949, p. 12, 15, 22 [Halocypridae by G & C] Recent, Atlantic. ’ Kempf (1986) in his Index and Bibliography of Marine Ostracoda listed the genus, giving M. rotundata (Müller 1890) as the type species, but without other comment. We note that Müller (1890) in his original description of Conchoecia rotundata gives the name as Conchoecia roduntata in the text and in the caption for his figures 41 – 43, but Conchoecia rotundata in the caption for his figure 44. In subsequent publications Müller consistently uses ‘ rotundata’, so we regard the spelling ‘ roduntata’ as a lapsus calami under Article 32.5 of the International Code of Zoological Nomenclature. Kock (1992) when he published the first adequate description of the genus Metaconchoecia, designated Conchoecia fowleri (Gooday 1981) as the type species. Kock’s designation was clearly pre-empted by Howe’s (1955), moreover his designation of M. fowleri (Gooday 1981) would seem inappropriate as this species was unknown when Müller (1906 a) first established his ‘ rotundata ’ group. It is clear from his name for the group that Müller regarded Conchoecia rotundata Müller 1890 as the typical form. Kempf (1995) subsequently not only accepted Kock (1992) as the authority for the genus, but also automatically accepted Kock’s designation of M. fowleri as the type species. Herein, we regard Howe’s (1955) designation of M. rotundata as the type species as being in full accord with the rules of nomenclature, so that Howe 1955 is the appropriate authority for the genus. The situation is even more complicated because Müller (1890) first described the species (females 1.15 mm long) from samples, which had been collected at two localities in the Pacific at 13 ° N 120 ° W and 1 ° S 100 ° W. He (1894) later described two sizes of Conchoecia rotundata from the Mediterranean — a short form which has a length of <1 mm and a long form. So the probability is that neither of the two forms from the Mediterranean is conspecific with the original concept of C. rotundata, and until material from the type locality in the tropical Pacific is examined uncertainty will prevail.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC1FFFC66FDDF8DDA36DFDD1.taxon	type_taxon	Type species. Conchoecia rotundata Müller 1890. Composition. Genus includes 14 described species, 2 described subspecies listed by original binomen (see Table 2 for later combinations) and 5 putative species or subspecies. Conchoecia acuta Gooday, 1981. Metaconchoecia sp. 1 aff. C. acuta (Gooday, 1981) (= “ Broad Form ” of Gooday 1981). Metaconchoecia sp. 2 aff. C. acuta (Gooday, 1981) (= “ Narrow Form ” of Gooday 1981). Metaconchoecia alta Chavtur, 2003. Metaconchoecia ampla Chavtur, 2003. Conchoecia australis Gooday, 1981. Metaconchoecia crassiseta Chavtur, 2003. Conchoecia discoveryi Gooday, 1981. Conchoecia fowleri Gooday, 1981. Conchoecia fowleri Form A of Gooday 1981. Conchoecia inflata Gooday, 1981. Metaconchoecia inflata lata Chavtur, 2003. Metaconchoecia longiseta Chavtur, 2003. Conchoecia obtusa Gooday, 1981. Conchoecia rotundata Müller, 1890. Conchoecia skogsbergi Iles, 1953. Conchoecia sp. aff. C. skogsbergi (Iles, 1953) (= Conchoecia skogsbergi sensu Angel 1968). Conchoecia subinflata Gooday, 1981. Metaconchoecia sp. nov. 1 sensu Chavtur 1992. Metaconchoecia sp. nov. 6 sensu Chavtur 1992. Conchoecia wolferi Gooday, 1981. The changes in the classification of these species are summarized in Table 2. The carapace outlines of females (lateral and ventral) are illustrated in Figure 3, all drawn to the same scale.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC1FFFC66FDDF8DDA36DFDD1.taxon	diagnosis	Differential diagnosis. Metaconchoecia species are small to medium length (0.71 – 1.75 mm) halocyprids that are cylindrical to globose in shape (length: height ratio ranging from 35 – 56 %). The LAG opens on the dorsal margin 7 – 17 % CL behind the tip of the rostrum. The RAG opens <7 % CL behind the posterior end of the hinge, and almost level with the dorsal margin. In males the capitulum of the frontal organ has a concavity near its base on its dorsal margin, and the A 1 e-seta armature consists of 9 – 19 pairs of slim spines that in some species become alternate proximally. The female frontal organ is fused into a single structure with the capitulum region shaped like a scalpel.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC1FFFC66FDDF8DDA36DFDD1.taxon	description	Redescription. Males. Carapace. Length range 0.71 – 1.73 mm. The carapace is relatively elongate. The maximum height of 42 – 56 % CL is located posterior to mid-length, so in lateral aspect the carapace tapers anteriorly. In specimens that have not splayed during preservation the breadth of the carapace is always slightly less than the height (29 – 54 % CL). In most species in ventral aspect the carapace curves smoothly in a single arc from the posterior margin to the rostrum (Fig. 3), and the rostra are always clearly visible. The LAG generally opens 7 – 10 % CL posterior to the tip of the rostrum (i. e. posterior to both the hindmost margin of the rostral incisure and the anterior end of the carapace hinge), but in M. discoveryi it opens further back at 14 – 17 % CL (i. e. slightly closer to the rostral tip than reported by Gooday (1981 )). The RAG opens close to the posterior dorsal corner, <1.0 – 6.5 % CL below the dorsal margin. The rostrum is relatively small and short, the distance from the tip of the rostrum to the anterior end of the carapace hinge is 5 – 11.5 % CL, and from the tip of the rostrum to the inner face of the incisure it is 3 – 7 % CL. All the species lack surface ornamentation. Frontal organ. The shaft is slightly shorter or similar in length of the A 1. The capitulum is short, broad, distally tapered and rounded. It extends beyond the end of the A 1. The shape of the capitulum varies, but in all species there is a concavity near its base on its dorsal side, which is opposite to a deep convex protuberance on the ventral edge. First antenna. Its length is 26 – 42 % CL and 3 – 3.5 times longer than the capitulum of the frontal organ. The aseta is S – shaped, swollen at its base, and lacks supplementary filaments. It is relatively long (14 – 39 % CL, mean 26 %) and in some species extends beyond the base of the limb. The c-seta is very short (2.5 – 6.5 % CL), and is shorter than the combined length of the third, fourth and fifth segments. The e-seta armature consists of 7 to 17 pairs of spines, but in five of the species the spines are arranged in pairs distally but become alternate proximally. The spines are generally long, slim and point basally, but in a few species they are short and stout. The e-seta is the longest of the setae on the limb (38 – 67 % CL and 1.4 – 2 times the length of the limb). The b- and d-seta are subequal and are only slightly shorter than the e-seta. Second antenna. The protopodite is large (41 – 53 % CL), and the first exopodite segment is usually quite thick and relatively long, 58 – 72 % (83 % in M. ampla) of the protopodite. The total length of the exopodite is 19 – 28 % CL. Some species have a short terminal seta on the first exopodite segment that curves around the base of the second segment. This seta has not previously been noted in the literature, so its significance and systematic value can not be assessed at present. The swimming setae are usually slightly longer than the protopodite. On the endopodite the longest seta (g) is almost as long (77 to 97 %) as the protopodite and is 34 – 50 % CL. The f-seta is shorter (27 – 44 % CL), and the sensory h-, i- and j-setae are 10 – 19 % CL. The f- and g-setae may either be cylindrical or terminally slightly flattened; they are always pointed. The h-seta is always simple and undivided. The c- and d-setae differ in length; they vary from being short and slim to being moderately long (i. e. as long as the segment that carries them). The e-seta also varies in size, but is always shorter than the segment on which it is inserted. The hook appendages on both the left and right endopodite are curved and terminally rounded. The hook on the left limb is always smaller and straighter than the one on the right limb. Labrum. The upper lip or labrum in common with all members of the tribe has a narrow deep cleft. It is fringed with short, stubby filaments. Mandible. The exopodite (Boxshall 1998) is present on the dorsal surface of the protopodite either as a small process on which is inserted a long, slim, pappose seta (Fig. 2 G) or there is just the seta and no process (Fig. 2 A). Subterminally on the dorsal surface of the first endopodite segment there is a moderately long seta that is usually armed with long setules. On the inner, ventral surface there are two setae, one of which is long and extends well beyond the end of the limb, and the other is shorter and just reaches to the end of the limb. The terminal segment carries seven setae, two of which are claw-like and spinose; the longest seta ranges from 77 – 107 % the length of the endopodite and 17 – 23 % CL. The coxale is long and about 80 % the length of the endopodite. Maxilla. The basale does not carry a seta. The exopodite has a complex structure and was described in detail by Skogsberg (1920). The endopodite is two segmented. The first segment has four setae on its anterior face, three setae on the posterior face, and a single lateral seta on the outer face. Terminally the second segment has three thick-walled hook setae, which are subtended by a pair of inner thin-walled setae. Fifth limb. The epipodial appendage carries three groups of four plumose setae in all the species examined. The setation of the limb shows minor interspecific differences but these may result from variation in how well the specimens are preserved, dissected and mounted. As discussed in Materials and Methods the segment which carries a long dorsal seta is considered to be the basale of a biramous limb and the long seta to be a vestige of the exopodite. Thus the main component of the limb is a 2 segmented endopodite and is not an exopodite as suggested by Iles (1953) and Skogsberg (1920). The terminal segment carries three setae of which the central seta is always the longest of the three (6.8 – 8.7 % CL). The dorsal seta is only a little shorter (75 – 97 %), and the ventral seta is the shortest, and is more variable in length (37 – 70 % of the central seta). Sixth limb. The epipodial appendage carries three groups of plumose setae, the dorsal group consisting of 6 or 7 setae, the central group usually 5 setae (4 in two species), and the ventral group 5 setae. The basale (note this is referred to as the first exopodite segment in publications prior to Kornicker 2003) generally has 3 or 4 ventral setae, and often a long lateral seta with long setules, but no dorsal setae (i. e. no vestige of an exopodite). The setae on the endopodite segments are always very short, except for the three terminal setae on the third segment. These are all similar in length and distally carry long secondary filaments. These setae are 36 – 50 % CL and 100 – 150 % the length of the limb. Copulatory appendage. The length of the appendage is 27 – 35 % CL. In the majority of species it is straight, but is curved in M. australis. The distal half is usually slightly broader than the proximal half. Terminally the appendage is either rounded or bluntly pointed. There are 2 to 7 oblique muscle bands. Females. Carapace. Lengths range from 0.71 – 1.75 mm. The carapace is slightly more elongate than in males. The maximum height of 42 – 55 % CL is posterior to mid-length, so that the carapace tapers anteriorly. The maximum breadth is at, or just anterior to mid-length. The LAG opens 9.3 – 16.5 % CL posterior to the tip of the rostrum, and the RAG opens 0 – 4.2 % CL behind the posterior end of the hinge, in much the same positions as in males. The rostra are small and short (LC 2 = 5 – 10.2 % CL) and the incisures are shallow (LC 3 = 2 – 8.8 % CL). As in the males the lateral flanks curve smoothly from the posterior margin to the rostra in the majority of species. The tips of the rostra are always just visible in ventral aspect. There is no surface sculpture. Frontal organ. The capitulum and shaft are fused in all species and are difficult to differentiate. The shaft is 19.5 – 26.5 % CL and the capitulum 9.5 – 12.5 % CL. The total overall length of the frontal organ is 31 – 38 % CL. The shaft is always much longer than the limb of the first antenna. The capitulum is scalpel-like and slightly downcurved. Its proximal end is expanded and then it usually tapers to a pointed tip. First antenna. The segments are always fused and the total length of the limb is 11.5 – 20.5 % CL. The e-seta is 31 – 38 % CL (i. e. 1.5 – 3 x the length of the limb and 1.5 – 2.5 x the lengths of the sensory a- to d-setae). The e-seta has thin, long spines along its trailing edge beyond the ends of the sensory setae. In common with most other species in the tribe, there is no dorsal seta on the second segment, except in two North Pacific species, Metaconchoecia alta and M. longiseta. Second antenna. The protopodite is 40 – 49 % CL. The exopodite is relatively long (i. e. 64 – 82 % the length of the protopodite) and thick. In some species, the base of the first segment is noticeably enlarged. The terminal setae on the endopodite are thin, parallel-sided and subequal in length, with tips that are either rounded or pointed. They are 52 – 85 % the length of the exopodite, 40 – 55 % the length of the protopodite and 1.6 – 2.6 x the length of the endopodite. Labrum, Mandible and Maxilla are similar in structure to those of males. Fifth limb. The epipodial appendage has three groups of 4 + 4 + 4 setae. The basale (considered to be the first endopodite in Skogsberg 1920 and Iles 1953) carries a group of three setae at mid-length and a single subterminal seta. Laterally there are two setae and also a long seta with long setules, which can appear to be inserted dorsally depending on how the limb is orientated. Dorsally there is a long subterminal seta that extends beyond the end of the limb. The first endopodite segment carries a pair of ventral setae and a single dorsal seta; all three extend beyond the end of the segment. The third segment carries three terminal setae with the central seta being the longest and close to 7.5 % CL. The dorsal and ventral setae are respectively 75 – 90 % and 37 – 60 % the length of the central seta. Sixth limb. The epipodial appendage also has three groups of (6 or 7) + 5 + 5 setae. The dorsal group consists of six long setae, which are supplemented with an additional short seta in some specimens. The basale carries 3 or 4 ventral setae. Laterally there is a long seta with long setules in about half of the species, but the presence or absence of this seta is too uncertain to be of value for identification. There is no dorsal seta. The first endopodite segment has only a very short ventral seta. The second segment carries a dorsal seta and a ventral seta inserted at mid-length; both are very short in all species. The terminal segment has three unequal setae. The central seta is always the longest and ranges in length from 9 – 13 % CL and 62 – 85 % of the limb. The dorsal seta is always longer than the ventral seta.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC1FFFC66FDDF8DDA36DFDD1.taxon	distribution	Distribution. The genus has been reported from all oceans, from epipelagic to abyssopelagic depths (surface to 5000 m). There are relatively few records from> 1000 m, but this is probably a reflection of the paucity of samples collected from bathypelagic and abyssopelagic depths. In the Atlantic Ocean the genus occurs in all areas and peripheral seas that have been investigated, including the Sargasso, Caribbean and Mediterranean Seas. Its previously reported bathymetric range is from the surface to 3600 m (Müller 1890, 1894, 1906 a; Vávra 1906; Fowler 1909; Granata & Caporiacco 1949; Iles 1953; Angel 1968 a, b, 1969 a, b, 1977, 1979, 1981 b, 1983 a; Deevey 1968, 1970, 1971, 1978 b; Angel & Fasham 1975; Deevey & Brooks 1980; Gooday 1981; Gonzales & Breman 1982; Ellis 1985; Angel et al. 2007). However, most of the early pre- 1970 records were collected with open nets and so the true depths of occurrence are uncertain. During a recent Polarstern cruise in the tropical and subtropical Eastern Atlantic specimens were caught in nets towed at depths of 4000 – 5000 m (unpublished data). In the Indian Ocean it has been reported from all latitudes from the Arabian Sea and the Bay of Bengal in the north to the Southern Ocean, at depths between 0 – 3423 m (Müller 1906 a, 1908; James 1975; George & Nair 1980; Hanai et al. 1980; Gooday 1981), however it is absent from midwater depths where there is oxygen-depletion (Graves, personal communication). It has been found in all areas of the Pacific Ocean investigated, from the Aleutian Islands to the Southern Ocean, from a wide depth range from surface to 7000 m (Müller 1906 b; Rudjakov 1962; Poulsen 1973; Chavtur 1977 a, b, c, 1992; Deevey 1978 a, 1982 a, 1983; Martens 1979; Hanai et al. 1980; Gooday 1981; Chen et al. 1983; Chen & Lin 1995). In addition, species have been reported from the Bering Sea and the Sea of Okhotsk (Chavtur & Shornikov 1974; Chavtur 1976, 1977 b, c, 1992). In the Southern Ocean species are common in all sectors as far south as 78 ºS occurring within the depth range 0 – 5190 m (Müller 1906 c, 1908; Skogsberg 1920; Hillman 1967, 1968, 1969; Deevey 1974, 1978 a, 1982 a, 1983; Hopkins 1985; Hopkins & Torres 1989; Naldi et al. 1992; Benassi et al. 1992; Kock 1992; Blachowiak-Samolyk 1999, Blachowiak-Samolyk & Zmijewska 1995, 1997; Blachowiak-Samolyk & Angel 2003, 2007; Chavtur & Kruk 2003). In the Arctic Ocean it has been recorded from an Ice Island station in the Central Arctic at 85 ºN, 91 ºW but from an unknown depth (Leung 1972, 1973, 1975). It has be recorded from 66 ºN, 2 ºE in the Norwegian Sea at a depth of 100 – 600 m (Angel 1968 a), but it has not been found in the Atlantic inflow water off Svalblad, despite intensive sampling (Blachowiak-Samolyk, personal communication), nor was it present in samples collected in the Canada Deep at 79 ° N to the north of the Bering strait (ARCOD samples, unpublished).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	description	1906 a Conchoecia rotundata group — Müller, p. 79 (part). 1949 Metaconchoecia — Granata & Caporiacco, p 15 (nomen nudum). 1953 Conchoecia — Iles, p 269 (part). 1962 Conchoecia — Rudjakov, p. 186 (part). 1968 C onchoecia — Deevey, p. 57 (part). 1973 Metaconchoecia — Poulsen, p. 70 (part). 1974 Conchoecia — Deevey, p. 362 (part). 1977 a Conchoecia — Chavtur, p 146 (part). 1980 Conchoecia rotundata group — Deevey and Brooks, p. 85 (part). 1982 a Conchoecia — Deevey, p. 148 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 141 (part). 1986 Metaconchoecia Granata & Caporiacco — Kempf, p. 498 (part). 1993 Conchoecia (= Metaconchoecia) — Angel, p. 158. 1999 Metaconchoecia — Angel, Figs. 9.58 – 76 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	etymology	Etymology. The name is derived from “ Mueller ” in honour of G. W Müller the pioneer of halocyprid taxonomy whose contribution overshadows us all, and “ - oecia ” from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived; this ending that has become standard for the genera of Conchoeciinae.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	type_taxon	Type species: Conchoecia glandulosa (Müller 1906 a). Composition: This genus includes at least two species, and possibly four further putative species: Conchoecia glandulosa (Müller 1906 a) Conchoecia macromma (Müller 1906 a) M. sp 1. aff. C. macromma (Muller 1906 a) sensu Deevey 1974 M. sp 2. aff. C. macromma (Muller 1906 a) sensu Deevey 1982 a M. sp 3. aff. C. macromma (Müller 1906 a) sensu Poulsen 1973 M, sp 4. aff. C. macromma (Müller 1906 a) sensu Angel 1981 b	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	diagnosis	Differential diagnosis. Metaconchoeciini species with elongate, tapering carapaces 0.84 – 1.95 mm in length. The LAG opens on the dorsal surface 20 – 35 % CL posterior to the tip of the rostrum. The RAG opens at the apex of an angle on the posterior margin about 15 % CL below the PDC. The male A 1 e-seta has an armature of 13 – 15 slim spines.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	description	Description. Males. Carapace. The length range is 0.84 – 1.95 mm. The carapace is elongate. The maximum height (43 – 50 % CL) is posterior to midlength, so the carapace tapers anteriorly. The LAG opens on the dorsal surface 20 – 35 % CL behind the tip of the rostrum and 13.5 – 17 % CL behind the anterior end of the hinge. The RAG opens 14.5 – 15.5 % CL below the PDC (i. e. 24 – 28 % of the carapace height). The rostrum is relatively well developed, and is 6 – 11 % CL. There is no surface ornamentation. Frontal organ. The capitulum is half the length of the shaft. Even so, it is comparatively long (15 – 20 % CL) and slim (little broader than the shaft). It is either straight or slightly bowed with a rounded end. The shaft is segmented with an articulation just posterior to where the retaining seta from the second segment of first antenna wraps around the shaft. The whole frontal organ extends well beyond the end of the A 1. First antenna. The limb segmentation is well defined, and the first segment is slightly shorter than the second. Overall, the length of the limb is 33.5 – 37.0 % CL and is similar in length to the shaft of the frontal organ. The a-seta is S-shaped and swollen at its base. Otherwise it is simple and long (16 – 21 % CL) and it extends back well beyond the suture between the first and second segments. The c-seta is short (4.0 – 8.2 % CL) and 75 – 125 % of the combined lengths of the third, fourth and fifth segments. The b-seta is slightly shorter than the d-seta, and the e-seta is slightly longer, 44 – 55 % CL (i. e. 1.5 x the length of the limb). The armature of the e-seta generally comprises 13 – 15 pairs (i. e. 26 – 30) of spines. The spines are usually long enough for the tips of one pair to overlap the bases of the next pair, but in M. sp 4. aff. C. macromma the 14 pairs of spines do not overlap. Second antenna. The protopodite is less than half the carapace length (46 – 47 % CL). The exopodite is quite slim, and the first segment is 40 – 50 % the length of the protopodite (i. e. 20 – 24 % CL). The g-seta is similar in length to the protopodite (40 – 48 % CL), and the f-seta is 90 % of the g-seta. Both these setae are slim with pointed ends. The h-, i- and j-setae are simple, undivided, and subequal (16 – 17.7 % CL). The c- and d-setae are slim and short. The e-seta is minute. The hook appendages on the endopodites are curved with rounded ends, and the left hook is, as usual, smaller and straighter. Labrum. In common with all the other genera in the tribe, the labrum is deeply cleft and flanked by short stubby filaments. Mandible (Fig. 2 I). The exopodite is developed as a process that carries a long, relatively slim seta with long setules. The coxale is relatively short, about half the length of the endopodite. The terminal segment of the endopodite carries the usual seven setae, two of which are developed into long claws. The longest claw is similar in length to the endopodite (20 – 23 % CL). Fifth limb. The setation of the limb matches the general pattern for the tribe. The middle terminal claw seta is 8 % CL; the dorsal and ventral setae are 75 – 90 % and <50 % of the length of the middle seta, respectively. Sixth limb. The terminal setae are subequal (35 % CL), and distally all three carry long setules. Caudal furca. The longest of the eight pairs of caudal spines is 19 % CL. There is an unpaired seta, which is 15 % the length of the longest caudal spine. Copulatory appendage. The appendage is about 31 – 32 % CL. It is straight and relatively parallel-sided with a rounded tip. There are 4 – 5 oblique muscle bands. Females. Carapace. The length range is 1.0 – 1.95 mm. The carapace is elongate. Its maximum height of 42 – 57 % CL occurs at or behind midlength. The LAG opens 20 – 35 % CL posterior to the tip of the rostrum and 15 – 17 % CL posterior to the anterior edge of the hinge. The RAG opens at the apex of an angle on the posterior margin, 17.5 – 20.5 % CL posterior to the posterior end of the hinge and 15.5 – 20.5 % CL below the dorsal margin. The rostrum is relatively well developed (Lrost is 9 – 12.5 % CL), whereas the incisure is somewhat shallower (5 – 12 % CL). There is no surface sculpturing. M. glandulosa is unusual in that in ventral aspect the rostrum is obscured by the anterior bulge of the margin of the carapace below the incisure (see Fig. 5), but in all forms of M. macromma the tips of the rostra are clearly visible in ventral aspect. Frontal organ. The shaft and capitulum are differentiated only by a shallow notch. The shaft (22 % CL) is longer than the limb of A 1. The capitulum is quite long (7.5 – 12.5 % CL) and is broader than the shaft. It is very slightly down-curved and may have a dorsal indentation near its base. It is inflated distally, and its end is either rounded or slightly pointed. The shaft is either one- or two-segmented (see M. glandulosa, Angel 1993 fig. 53). First antenna. The basal limb segments are fused, and the limb’s overall length is 15 – 17 % CL. The sensory setae are simple (10 – 14.3 % CL) and less than half the length of the e-seta (27 – 34.5 % CL). Along its trailing edge the e-seta has fine spines distal to the ends of the other setae. In common with the majority of species in the tribe, there is no dorsal seta. Second antenna. The protopodite is relatively short (36 – 42 % CL). The exopodite is slim and long relative to the protopodite (62 – 80 % of its length). The swimming setae are slightly longer than, or similar in length to, the protopodite. The g-seta on the endopodite is 23 – 31 % CL, and is only a little longer than the other four setae. All these setae are unflattened and have pointed tips. Labrum, Mandible and Maxilla are similar in structure to those of males. Fifth limb. The epipodial appendage has three groups of 4 + 4 + 4 setae in M. glandulosa, but there are no data for M. macromma. Ventrally the basale carries a group of three setae at midlength and one or two subterminal seta. Laterally there are two or three setae. Dorsally there is both a long bare seta that extends beyond the end of the limb and a shorter seta with long setules. The first endopodite segment carries two ventral setae and one dorsal seta, all of which extend beyond the end of the segment. The terminal segment carries three terminal setae; the central seta is the longest and is 7.5 – 8.5 % CL. The dorsal and ventral setae are respectively 80 % and 60 % the length of the central seta. Sixth limb. The epipodial appendage also has three groups of 6 (or 7) + 5 + 5 setae. The basale carries 4 or 5 ventral setae. Laterally there are up to three setae, and dorsally there is a long subterminal seta and a shorter seta with long setules. The first endopodite segment has a very short ventral seta, but no dorsal seta. The second segment carries a medial dorsal seta and a medial ventral seta, both of which extend almost to the end of the segment. The terminal segment has three unequal setae. The central seta is the longest, and is 15 % CL in M. glandulosa, and 10 – 12 % CL in M. sp 4. aff. C. macromma. The dorsal and ventral setae are respectively 80 % and 60 % of the longest central seta.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	discussion	Remarks. M. glandulosa is relatively uncommon in collections, but this moderately-sized, deep bathypelagic species occurs regularly whenever samples have been collected from depths> 2000 m in the North Atlantic. Like many deep-living species it is fragile and so few specimens have been collected in good condition. It has a large size range. Females collected from the North and Equatorial Atlantic range 1.30 – 1.74 mm (mean 1.46 mm, n = 29), and males range 1.36 – 1.80 mm (mean 1.52 mm, n = 11). These are unusually broad size ranges, casting doubt on whether all these specimens are the same species. Similarly, Müller (1906 a) in his original description of the species reported the lengths of females and males from the southern Indian Ocean to be even bigger at 1.9 mm and 1.85 mm, respectively. So are these Indian Ocean specimens conspecific with the Atlantic specimens? This question cannot be resolved until specimens from the Indian Ocean can be examined. In addition, Chavtur (1976) reported a relatively small male (1.4 mm) from the N. E. Pacific. There are similar problems with M. macromma. This species is either mesopelagic or bathypelagic. Müller’s (1906 a) original description is inadequate by modern standards, and several of the subsequent descriptions are little better. Müller (1906 a) reported it both from between 24 ° N and 2 ° S in the Atlantic and from 13 ° N and 2 ° S in the Indian Ocean but failed to specify a type locality. Deevey’s (1974) Hudson 70 material of Conchoecia macromma may have been collected from similar water masses as Müller’s (1906 a) Atlantic material, but from much further south (40 ° S). She reported lengths were longer and she also illustrated (p. 364, fig. 5) HC 2 to be 13 – 14 % CH (visà-vis 25 % in Müller’s (1906 a) illustration), and LC 2 to be 35 % CL (vis-à-vis 24 % in Müller’s (1906 a) illustration). Deevey also illustrates the maximum carapace height as being posterior to midlength (vis-à-vis at midlength in Müller’s (1906 a) illustration). These differences may well be significant so we are designating her 1974 material as M. sp 1. aff. C. macromma. Deevey (1982 a) reported on a single female specimen from the Southern Ocean, which also deviates from Müller’s type description as follows: 1. The carapace is longer 1.34 mm (vis-à-vis 1.00 – 1.07 mm) and higher (55 – 60 % of length). 2. HC 2 is 21 – 22 % of the height down the posterior margin (vis-à-vis 25 %). 3. The length of e-seta of the A 1 is double or more the lengths of the limb and a- to d-setae (vis-à-vis 1.5). This Southern Ocean female also differed from M. sp 1. aff. C. macromma in that LC 2 is shorter (20 % CL visà-vis 35 % CL). Hence we designate Deevey’s Southern Ocean specimen as M. sp 2. aff. C. macromma. Poulsen (1973) described and illustrated a single female of Metaconchoecia macromma collected at Dana station 3613 in the S. W. Pacific at 22 ° 43 ’ S, 166 ° 06 ’ E. His description also deviates from both Müller’s type description and both of Deevey’s descriptions. Poulsen’s specimen differs from Müller’s type description as follows: 1. The carapace is longer (1.2 mm) and higher (> 50 % CL). 2. The rostrum is relatively large (LC 3 is 12 % CL vis-à-vis 6 %). 3. The maximum carapace height is posterior to midlength. 4. HC 2 is 24 % CH. 5. LC 2 is 30 % CL. 6. The A 1 e-seta is twice the length of the limb and 2.5 – 3 x times the lengths of the a- to d-setae. 7. The structure of the capitulum is different. We designate Poulsen’s specimen as M. sp 3. aff. C. macromma, noting that it is most similar to M. sp 1. aff. C. macromma, except for the rostrum is larger, and LC 2 is shorter. It differs from M. sp 2. aff. C. macromma in the positions of the openings of the asymmetric glands (especially the LAG), its rostrum being larger (6 % in M. aff. macromma 2) and the A 1 e-seta being relatively longer (2.5 – 3 x the lengths of the a- to d-setae). Finally, Conchoecia macromma of Angel (1981 b) shows only minor differences to the specimens described by Müller (1906 a). His material was collected at 0 ° 23 ° W (although this is not stated in the publication), which is within the latitudinal range of Müller’s Atlantic material. Since Müller (1906 a) neither designated a type locality, nor cited where the specimens he illustrated were collected, it is unclear how significant the differences are between his description and Angel’s. So were Müller’s drawings based on specimens from the Indian Ocean? It is impossible to tell until further material is examined from the Indian Ocean. So here we designate Angel’s (1981 b) material as M. sp 4. aff. C. macromma. There are differences in the morphology of the A 1, the c-seta of Angel’s male is shorter (three-quarters the combined lengths of segments of the third, fourth and fifth segments vis-à-vis subequal in M. macromma s. s.), the e-seta armature consists of 14 pairs of somewhat short spines (vis-à-vis 15 pairs of longer spines in M. macromma s. s.) and the seta is about double the length of the limb (vis-à-vis 1.5 x in M. macromma s. s). Subsequent measurements of Angel’s material show the female e-seta is 1.7 x the length of the limb and 2.2 x as long as setae a – d (vis-à-vis 1.5 x and 1.5 x respectively in M. macromma s. s.). His unpublished measurements of 25 specimens are slightly less extreme, giving the mean lengths of the e-seta, limb and a- to d-setae as 27 %, 16 % and 13 % CL, respectively. The carapace lengths of Angel’s material are consistent with Müller’s (females 0.98 – 1.16, n = 36; males 0.96 – 1.10, n = 37), but are smaller than reported for the other forms. Table 3 summarizes the variations in the carapace characteristics of all these forms. Figure 5 reproduces the original published drawings of the female carapaces at identical scales and clearly demonstrates that neither Deevey’s nor Poulsen’s specimens are likely to be the same as Müller’s. Clearly a further re-appraisal is needed.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC04FFCD6FDDF8D1A493FD64.taxon	distribution	Distribution. Atlantic Ocean: found between 42 ºN and 44 ºS (Müller 1906 a, 1908; Iles 1953; Deevey 1968, 1974; Angel 1979, 1981 b, 1983 a). Indian Ocean: known from between 13 ºN and 29 ° S (Müller 1906 a; Leveau 1967; Gooday 1981). Pacific Ocean: occurs in the area of the Kurile-Kamtchatka and Aleutian Trenches (Rudjakov 1962; Chavtur 1977 a, b, c, 1992), China Seas (Chen et al. 1983; Chen & Lin 1995) and from 22 ºS to 40 ºS (Poulsen 1973; Martens 1979; Deevey 1983). Southern Ocean: recorded as far south as 60 – 64 ºS in the Pacific sector (Deevey 1982 a, 1983). The described overall depth range is 200 – 8000 m, but once again the maximum depth cited may be misleading as many of the records are from samples collected by open vertically hauled nets. (Note: neither Deevey (1982 a) nor Poulsen (1973) had any males, so males of M. spp 2 and 3. aff. C. macromma are unknown).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	description	1982 a Conchoecia ‘ rotundata’ group — Deevey, p. 148 (part). 1986 Metaconchoecia Granata & Caporiacco — Kempf, p. 498 (part). 1987 Conchoecia goodayi — Chavtur, p. 1258 (part). 1987 Conchoecia — Chavtur, p. 1258 (part) 1992 Metaconchoecia — Kock, p. 68 (part). 1995 Metaconchoecia Kock — Kempf, p. 149 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	etymology	Etymology. The name is derived from “ Vityaz ” to commemorate the famous Russian research vessel from which the type species was first sampled, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	type_taxon	Type species: Metaconchoecia goodayi Chavtur 1987 Composition: The genus includes Metaconchoecia goodayi Chavtur, 1987. Metaconchoecia sp. 1 aff. Conchoecia goodayi Chavtur, 1987 Conchoecia lunata Deevey, 1982 a. Vityazoecia n. sp 1 aff. V. lunata (Deevey, 1982 a) new record Vityazoecia n. sp 2 aff. V. lunata (Deevey, 1982 a) new record	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	diagnosis	Differential diagnosis. The genus includes the species with the LAG opening> 30 % CL behind the tip of the rostrum. The RAG opens just over 5 % CL below the hinge line. The curve of the posterior margin of the carapace is almost smooth but is interrupted by a slight angle just below the PDC. The carapace is covered with a faint sculpturing of fine horizontal striae. In the male, the A 1 a seta has two supplementary basal filaments.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	description	Description. Males. Very few species of either species have been collected, and so the description of males given below has been supplemented with details of a male V. n. sp. 1 aff. lunata recently caught at a depth of 4000 – 5000 m (Ron Brown Cruise 0603, 21 / 04 / 2006, 25 ° 03.367 ’ N, 60 ° 37.536 ’ W, MOC 10 # 4 net 1). Carapace. The length range is 1.45 – 1.50 mm (Fig. 5). The carapace is relatively high (45 – 50 % CL) and quite broad (45 % CL). The maximum carapace height is either at midlength or slightly posterior to it. The LAG opens 30 – 36 % CL behind the tip of the rostrum. The RAG opening is displaced 10 – 18 % of the height down the posterior margin. The rostrum is relatively well developed (Lrost = 9 – 11 % CL) and is a little longer than the incisure (LC 3 = 9.5 % CL). There is a faint sculpturing of straight lines that run approximately parallel to the ventral and dorsal margins; species of Vityazoecia and Juryoecia are the only Metaconchoeciini to have clear sculpturing on the carapace. Frontal organ. There is a clear suture between the shaft and the capitulum. The shaft is long (32.5 % CL) and also is sutured close to its midpoint. The capitulum is quite long (15 % CL), slim, and almost straight; it extends well beyond the end of the A 1. First antenna. The limb is clearly segmented with the length of the first segment being shorter (65 %) than the second. Overall, the limb is similar in length (32.5 % CL) to the shaft of the frontal organ and is about 2.5 x the length of the capitulum. The a-seta is quite long (10 % CL) and carries an additional short to medium-length filament, which is inserted near its base in V. goodayi and at midlength in V. lunata. The c-seta is about 6.5 % CL, which is double the combined lengths of the third, fourth and fifth segments. The armature of the e-seta consists of 19 – 22 pairs of stout medium-length spines, which are close together distally and become more spaced out proximally. The e-seta is long (60 % CL and 1.5 x the length of the limb). The d-seta is either slightly shorter or similar in length to the e-seta, and the b-seta is a little shorter. Second antenna. The protopodite is quite short 43 – 44 % CL. The first exopodite segment is slim and ~ 60 % the length of the protopodite. It does not have a terminal seta. The swimming setae are relatively long (68 % CL in V. n. sp. 1 aff. lunata). Both the long setae on the endopodite are longer than the protopodite (g-seta 56 % CL; f-seta 50 % CL). They are slightly flattened distally and end in sharp points. The sensory setae (h-, i- and j-) are subequal (15 % CL). These setae are simple and without a side branch, but in V. lunata their basal halves are swollen. The c- and d-setae are slim, bare and short, and the e-seta is minute. The hook appendages are terminally rounded; the left hook is, as usual, the smaller. The right hook has a short basal hasp followed by a rounded right angle. It is then straight before curving quite sharply through ~ 60 ° before straightening out again. Labrum. Deeply notched and with few, very short, stubby, fringing setae. Mandible (Fig. 2 F). The exopodite is well developed as a process in V. goodayi and bears a long relatively stout seta with long setules; whereas in V. lunata there is the seta with long setules but no process. The toothed edge of the basale has the usual two spine teeth and six triangular cutting teeth, but Deevey 1982 a states explicitly and illustrates it as having 7 cutting teeth (her fig 23 h). None of the specimens we have examined show this characteristic. The coxale is relatively short, two-thirds or less than the length of the endopodite. The longest terminal seta on the endopodite is quite long (21 % CL and 85 % the length of the limb). Fifth and sixth limbs. The fifth limb is similar to those of the other genera, but the sixth limb appears to have only a very short seta at two-thirds length on the ventral surface of the first segment, and a small medial seta dorsally and another ventrally on the second segment. The three terminal setae are subequal 46 % CL, and all three distally carry long setules. Caudal furca. The longest of the eight pairs of spine setae is 16 % CL, and there is an unpaired slim seta at the dorsal end of the paired setae. Copulatory appendage. This appendage is relatively large in V. goodayi 36 % CL, but is quite small in V. lunata 21 % CL. The anterior margin is straight or very slightly concave, whereas the posterior margin is clearly arched; so the appendage is broadest at midlength and tapers to its rounded tip. There are 3 – 5 slightly oblique muscle bands. Females. Carapace. This description has been supplemented with observations on two females sampled at a depth of 2858 – 2921 m in an epibenthic sledge (Polarstern cruise PS 61, station 114 / 4, 17 / 02 / 2002, 61 ° 43.59 ’ S; 60 ° 42.52 ’ W). Their lengths are 1.42 and 1.50 mm. The carapace is relatively high and slightly elongated. The maximum height is slightly posterior to midlength. The LAG opens 30 – 36 % CL behind the tip of the rostrum. The RAG is displaced 14 – 15 % of the height down the posterior margin. The rostrum is quite large, LC 3 is 10 – 11 % CL, and Lrost is 13.5 % CL. As in the male, there is a faint sculpturing of longitudinal lines that lie parallel to the ventral and dorsal margins. Frontal organ. The capitulum and shaft are fused. Taking the slight notch in the dorsal surface to indicate the base of the capitulum, the length of the capitulum is only slightly shorter than the shaft. The whole organ is straight or slightly down-turned with a rounded tip that is finely spinose along the ventral margin in V. lunata. The shaft is similar in length to the A 1 limb, so the whole organ is 1.5 – 2 x the length of the A 1 (i. e. 34 % CL in V. lunata). First antenna. The basal segments are fused, but the first segment appears to be about half the length of the second. There is no dorsal seta. The e-seta (25 % CL) is nearly double the lengths of the sensory setae (13.5 % CL), and 1.5 x the limb (17.6 % CL). It carries fine spines along its trailing edge distal to the ends of the sensory setae. Second antenna. The protopodite is quite short (40 % CL). The first exopodite segment is relatively thin and long, 60 % the length of the protopodite. The length of the complete exopodite is 75 % that of the protopodite. The terminal setae on the endopodite are subequal, parallel-sided and pointed. They are relatively long, about 75 % the length of the protopodite (i. e. similar to the exopodite), and about 3.5 x the length of the first endopodite segment. Mandible. The structure of this limb is similar to that of the male. Fifth limb. The ratios of the lengths of the terminal seta (dorsal to ventral) are close to 85: 100: 60 with the longest seta being 8.5 % CL. Sixth limb. The ratios of the lengths of the terminal setae are close to 70: 100: 50. The longest, central seta is 12.5 % CL. Caudal furca. Similar to that of the male.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	discussion	Remarks. A carapace of a male (or an A – 1 male) that closely resembles V. goodayi was found in a deep sample from the North Pacific (RV Vityaz 1966, St. 5612, 45 º 43 ’ N; 153 º 25 ’ E, 5000 – 4000 m). It is identified here as V. sp. 1 aff. goodayi (Chavtur 1987), since it differs from the type material (Chavtur 1987) in having the RAG displaced about 12 – 13 % the height (c. f. 17 % in V. goodayi) down posterior margin, and the LC 3 is 36 % (c. f. 31 – 32 % in V. goodayi). Otherwise the size and shape of this isolated carapace were consistent with V. goodayi. Specimens of V. lunata, which have been used to help refine the description of the genus, were collected from the RV Polarstern in deep samples collected in the Southern Ocean (a female at Station 80 – 9, date 23 / 2 / 2005, 70 ° 38.46 ’ S, 14 ° 42.87 ’ W, depth 3102 – 3136 m, and a male at station 16 – 10, date 26 / 1 / 2002, 41 ° 07.57 ’ S, 9 ° 55.97 ’ E, depth 2858 – 2921 m). Recently, during a Census of Marine Zooplankton cruise to the southwest Atlantic on the RV Ron Brown, another very similar female specimen, designated herein as V. n. sp. 1 aff. lunata, was taken in a MOCNESS 10 net (Wiebe et al. 1976) at 25 ° 03.37 ’ N, 60 ° 37.54 ’ W at a depth of 5000 – 4000 m. So this species appears to be very widely distributed at deep bathypelagic to abyssopelagic depths. Another female initially identified as C. lunata, but now designated as V. n. sp. 2 aff. lunata, was taken at Discovery station 9541 # 22, date 20 / 4 / 1977, at 20 ° 08 ’ 54 ” N, 21 ° 25 ’ 00 ” W, at a depth of 3780 – 3870 m (within 100 m of the sea floor). However this female is 1.70 mm long, and shows a number of minor deviations from the descriptions given above.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC0BFFC86FDDFC70A099FED2.taxon	distribution	Distribution. Pacific Ocean: regions of the Kurile-Kamtchatka, Aleutian and Japan Trenches at depths of 2000 – 5000 m (Chavtur 1977 c, 1992), in the Pacific sector of the Southern Ocean between 47 ° – 60 ° S at depths of 3500 – 3750 m (Deevey 1982 a), in deep hauls in the N. E. and N. W. Atlantic at depths> 3780 m, and in the Atlantic sector of the Southern Ocean in epibenthic sled samples (Polarstern stations 16 – 10 and 80 - 9 at depths of 2850 – 3150 m - see above).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	description	(Figs 6 – 10) Synonymy: 1977 a Metaconchoecia skogsbergi — Chavtur, p. 145 – 146 (part). 1977 b Metaconchoecia skogsbergi — Chavtur, p. 30 (part). 1977 c Metaconchoecia skogsbergi — Chavtur, p. 20 (part). 1992 Metaconchoecia sp. nov. 7 — Chavtur, table 2 (list).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	etymology	Etymology. The specific name “ distoglandula ” is derived from the Latin verb disto, meaning to stand apart, to be distant; and the Latin noun glandula, meaning one of the glands in the neck, tonsils; referring to the position of the LAG, which opens well posterior of the tip of the rostrum.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	materials_examined	Holotype. IBM 2822: adult female; length 1.6 mm, appendages mounted on slide and valves in alcohol, in collection of the Museum of Zhirmunsky Institute of Marine Biology, Vladivostok, Russia. Type locality. RV Vityaz Cruise 39, station 5612 (sample 77) 45 º 43 ’ N, 153 º 25 ’ E, depth 5000 – 6000 m, 31 July 1966, using a Bogorov-Rass Net (mouth area 1.0 m ²). Paratype. IBM 2823: adult male, length 1.90 mm, appendages mounted on slide and valves in alcohol, also in collection of the Museum of Zhirmunsky Institute of Marine Biology, Vladivostok, Russia. RV Vityaz Cruise 39, station 5617 (sample 121) 45 º 49 ’ N, 153 º 33 ’ E, depth 6000 – 7000 m, 5 August 1966. Additional material. RV Vityaz Cruise 39, 1966: two females (lengths 1.47 and 1.5 mm), immature male (only carapace, 1.45 mm), and three juveniles at station 5612, sample 94, 45 º 43 ’ N, 153 º 25 ’ E), depth 4000 – 5000 m, 31 July 1966; four females (1.35 – 1.47 mm) at station 5628, sample 223, 43 º 59 ’ N, 149 º 46 ’ E, depth 4000 – 5000 m, 31 August 1966.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	description	Description. Male. Carapace (Figure. 6 A). The length of the adult specimen is 1.9 mm. The carapace is elongate with a maximum height of 50 % CL. The maximum height is behind midlength, so the shell slightly tapers anteriorly. The shoulder vaults are rounded, but weakly developed. The dorsal margin is straight. The posterior dorsal corner has a distinct apex, but the angle is rounded. The posterior and ventral margins merge in a smooth curve, so there is no clear posterior ventral corner. The rostrum is well developed with a pointed tip. The rostral incisure is fairly deep. The RAG opens just below the posterior dorsal corner, whereas the LAG opens on a protuberance that is clearly seen in profile to be situated well behind the tip of the rostrum (39 % CL). There is no sculpturing on the carapace of the male but is present on the female carapaces. There are no obvious medial glands. Frontal organ. The shaft just reaches level with the distal end of the second segment of the A 1. However, the capitulum of the holotype has been lost, and where the break occurred is uncertain. First antenna (Fig. 6 B – D). The segmentation of the limb is distinct. The a-seta is branched with two basal filaments, both of which are shorter than the main branch. The a-seta is quite short and does not extend back quite as far as the articulation between the first two limb segments. Both the b- and the d-setae have a short row of closelyspaced fine spines of various lengths that are inserted level with the distal ends of the armature on the e-seta. These setae are much longer than the limb, but the ends of both are broken. The c-seta is relatively thin and long 1.5 x the combined lengths of the limb’s third, fourth and fifth segments. The e-seta is 1.7 x the length of the limb. Its armature consists of 12 pairs of thin, long spines, which lie pointing proximally at an acute angle to the seta. Distally they are close together but become more spaced out proximally. Distal to the armature the e-seta is parallel-sided and unflattened; it ends in a pointed tip. The first segment of the limb contains some dark pigment cells. Second antenna (Figs. 6 E – G). The protopodite contains some dark pigment cells. The exopodite is relatively thin and long, 80 % the length of the protopodite. The a- and b-setae on the first endopodite segment are bare. The c- and d-setae on the second endopodite segment are of medium length and slim. The e-seta is minute. The hook appendage on the right limb (Fig. 6 F) has a strongly developed short basal hasp and a long curved distal section. It ends in a rounded swelling with a number of subterminal ridges. The hook appendage on the left limb (Fig. 6 G) is smaller, with a relatively short and only slightly curved distal section; it has a small terminal swelling with indistinct subterminal ridges. The g-seta, the longest seta, is 4 x the length of the first endopodite segment and 5 x the lengths of the sensory setae. It is 1.5 x and 1.25 x the lengths of the exopodite and protopodite respectively. Both the f- and g-setae are slightly flattened terminally. Mandible (Figs 6 H, I; 7 A – E). The coxale is short (Fig. 6 I), about half the length of the endopodite. Its toothed edge has a straight anterior section followed by about 10 teeth, of which the posterior-most tooth is large and triangular (Fig. 7 D). The distal list has 3 large posterior teeth and is followed by 8 – 10 small and rounded anterior teeth (Fig. 7 C). The proximal list is armed with about 23 small and rounded teeth (Fig. 7 C). The masticatory pad has 4 narrow rounded flaps, which are densely covered with exceedingly fine, rather short spines (Fig. 6 H), 4 stout teeth, numerous filaments with bifurcated tips, and stiff setules. The toothed edge of the basale has the usual two tubular teeth, of which the posterior one is pointed and carries a few spines, and the second is bluntly rounded and bare (Fig. 7 A, B). Adjacent to the tube teeth are 6 triangular cutting teeth; the first of which is slightly offset from the others, and lacks the secondary cusps and serrations that are present on the other five. In addition, there is a large inner lateral tooth. The basal endite bears one anterior and two short lateral setae. The epipodite is relatively well developed, wide and rounded on top. The exopodite is reduced to a minute triangular protuberance that carries a long, stout seta with fine setules, which is similar in length to the first endopodite segment (Fig. 2 A). The first endopodite segment dorsally has a subterminal seta that is short and pilose, laterally a long seta with short setules, and ventrally a shorter seta that also has setules. The second segment has three distodorsal setae and two distoventral setae. The third segment is armed with the usual seven terminal setae; the main claw-like seta is similar in length to the endopodite and somewhat longer than most distodorsal seta on the second endopodite segment. Maxilla (Fig. 7 F, G). The basale has no seta. The first endopodite segment is broad. On its anterior side it has four medial setae with short setules, and on its posterior side three setae, and there is a short distomedial lateral seta that extends to just beyond the end of the limb. The distal ventral margin of the first segment is armed with about 10 short spines. The terminal segment is comparatively short and wide. Its anterior claw is about twice as long as the posterior claw. The structures of the precoxal and coxal endites are obscure. Fifth limb (Fig. 7 H, I). The epipodial plate carries three groups of four plumose setae. The first endite of the protopodite has a seta with long setules and two shorter setae with short setules. The second endite has 8 – 9 setae; two are clawlike, and one or two of the others are long setae with long setules; the remaining five are short to medium-length with short setules. The basale has 7 ventral setae, and dorsally a seta with short setules and a long seta with long setules. This long dorsal seta is interpreted as being the remnant of the exopodite by Boxshall (1998) and Kornicker (2003) on the basis of the musculature. The first endopodite segment has two ventral setae and one dorsal seta with short setules. The second segment has three terminal setae; the central seta is long and claw-like and is flanked by two shorter setae. Sixth limb (Fig. 8 A, B). The epipodial plate carries three groups of long plumose setae (dorsal to ventral) of 7 (the dorsal-most seta is short), 5 and 5. On the basale there are three short ventral setae and laterally a long seta with long setules and a shorter bare seta. The first endopodite segment has only a tiny ventral seta. The second segment has a minute medial seta on both its dorsal and ventral margins. The terminal segment is armed with the usual three long setae, carrying long setules along their distal quarters. Seventh limb (Fig. 8 C). The terminal segment bears the usual two unequal setae (the longer 3 x longer than the shorter). Copulatory appendage (Fig. 8 E). The appendage is straight and parallel-sided with a rounded tip. Its length is 33 % CL. Caudal furca (Fig. 8 D). Each lamella bears eight claw setae, and there is an unpaired seta with short setules between the lamellae dorsal to the smallest pair of claw setae. The inner surfaces of the lamellae are covered with fine setules. Female. Carapace. (Fig. 9 A – F). The lengths of adult females range from 1.47 – 1.60 mm (mean 1.52 mm). The maximum height of the shell (50 – 53 % CL) is posterior to midlength, so the carapace tapers anteriorly. In the ventral aspect, the maximum width (43 – 46 % CL) is at midlength. The opening of the LAG varies from 30 to 39 % CL behind the tip of the rostrum. The surface of the carapace has a faint sculpturing of fine longitudinal striae. In all other respects it is similar to the carapace of the male. Frontal organ (Fig. 9 G, H). The capitulum is fused to shaft. It widens distally and is covered with minute spines. Assuming that these fine spines are indicative of the capitulum region, then the shaft clearly extends well beyond the end of the A 1 limb. The whole organ is about double the length of the limb. First antenna (Fig. 9 H, I). Each of the sensory setae a – d has a short proximal branch near its base; the side branch on the a-seta is slightly longer than the side branches on the other setae. The e-seta is 2.5 x the lengths of both of the sensory setae and the limb. Its trailing edge carries a row of minute spines. The surfaces of the second and third segments of the limb are also covered with minute spines. Second antenna (Fig. 9 J, K). The protopodite contains a few dark pigment spots. The exopodite is long, 90 % the length of the protopodite. The a-seta on the first endopodite segment is just over half the length of the b-seta. On the second segment there is no c-, d- or e-seta. The terminal setae (f – j) are subequal. They are 75 % and 88 – 95 % of the lengths of the protopodite and exopodite, respectively, and three times the length of the first endopodite segment. Distally they become widened and flattened and have pointed tips. Mandible (Fig. 10 A – C). The basal endite bears one short seta anteriorly, and one long and 2 short setae laterally. Dorsally the second endopodite segment is armed with three distal setae, two short and slim, and one long and thick. The longest terminal claw seta is almost as long as the endopodite. The distal list on the coxal endite (Fig. 10 C) has one large stout posterior tooth; otherwise, the characters are similar to the male. Maxilla. Similar to that of the male. Fifth limb (Fig. 10 D). Similar to that of the male except there are ten (rather than nine) setae on the first exopodite segment. Sixth limb (Fig. 10 E, F). The limb is similar to that of the male, except: a. The first endopodite segment bears five long setae with long setules. b. The setae on the second and third segments are relatively long with short setules. c. The main terminal seta is considerably longer than the epipodial plate and about half the length of the limb. Seventh limb (Fig. 10 G). Proximally the limb is noticeably widened; in all other respects it is the same as in the male. Caudal furca (Fig. 10 H). It is similar to that of the male.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	discussion	Remarks. This species is closely related to J. abyssalis (Rudjakov, 1962). Table 6 lists some of the characters that discriminate between the two species.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC33FFF16FDDFF72A3F0FD54.taxon	distribution	Distribution. The new species has been caught in the Kurile-Kamtchatka Trench in the depth range 4000 – 7000 m. A male specimen that closely resembles J. distoglandula was recently caught in the western tropical Atlantic (RV Ron Brown Cruise 0603, 26 April 2006, MOC 10 # 7 Net 1, depth 5000 – 4000 m, position 14 ° 16.930 ’ N, 54 ° 21.960 ’ W). It is only 1.36 mm in length, but otherwise not only are its carapace characteristics identical, but also the A 1 e-seta has two accessory branches. However, the A 1 e-seta armature consists of 20 pairs of slim basally pointing spines, so this is a new species.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	description	1906 a Conchoecia rotundata group — Müller, p. 79 (part). 1908 Conchoecia — Müller, p. 77 (part). 1920 Conchoecia rotundata group — Skogsberg, p. 648 (part). 1955 Metaconchoecia — Howe, p. 118 (part). 1973 Metaconchoecia — Poulsen, p. 70 (part). 1974 Conchoecia — Deevey, p. 367 (part). 1978 a Conchoecia — Deevey, p. 55 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 159 (part). 1982 a Conchoecia rotundata group — Deevey, p. 148 (part). 1982 Conchoecia — Jazdewski et al. (part). 1986 Metaconchoecia — Kempf, p. 486 (part). 1992 Metaconchoecia — Kock, p. 68 (part). 1992 Conchoecia — Benassi et al. p. 71 (part). 1997 Metaconchoecia — Blachowiak-Samolyk and Zmijlewska, p. 80 (part). 1997 Metaconchoecia — Gollasch, p. 224 (part). 1999 Metaconchoecia — Angel, Figs 9.58 – 76 (part). 2002 Metaconchoecia — Blachowiak-Samolyk and Osowiecki, p. 140 (part). 2003 Metaconchoecia — Chavtur and Kruk, p. 170 (part). 2007 Metaconchoecia — Blachowiak-Samolyk and Angel p. 71 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	etymology	Etymology. The name is derived from the Latin adjective austrinus, meaning southern, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	type_taxon	Type species. Conchoecia isocheira (Müller, 1906 a). Composition. The genus is monospecific, containing only Austrinoecia isocheira (Müller, 1906 a) a species that is endemic to the Southern Ocean.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	diagnosis	Differential diagnosis. Small (0.76 – 1.12 mm), deep mesopelagic species. Females tend to be slightly larger than males. The maximum carapace height is just anterior to midlength in males, but is just posterior to midlength in females. The LAG opens just posterior to the anterior end of the hinge. The RAG opens at the apex of an angle in the posterior margin at about 15 % CH below the hingeline. The d-seta on the male A 1 is longer than the e-seta. The e-seta armature consists uniquely of a single row of 7 – 9 hyaline flanged spines. The copulatory appendage has a characteristic deep terminal indentation on its anterior margin.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	description	Description. Males. Carapace. The length range is 0.76 – 0.95 mm (mean 0.86 ± 0.036 mm). The carapace is relatively short and high. The maximum height of 50 – 61 % CL occurs anterior to midlength. The breadth can exceed the height in some specimens, but it is generally 53 – 54 % CL. The LAG opens 12 – 15 % CL behind the tip of the rostrum and 3.5 % CL posterior to the anterior end of the hinge. The RAG opens on the apex of a slight protuberance on the posterior margin 13 – 17 % CH below the dorsal hinge line. The rostrum is quite well developed, 7 – 9 % CL. There is no surface ornamentation. Frontal organ: There is a clear septum dividing the capitulum from the shaft. The shaft is quite short (27 % CL), and the capitulum is even shorter (12 % CL). It is barely thicker than the shaft. It is either straight or slightly concave, and its tip is rounded. The end of the capitulum barely extends beyond the end of the A 1. First antenna. The limb is clearly segmented and is about 3 x the length of the capitulum. The a-seta is simple and extends back almost to the proximal end of the second segment. The c-seta is similar in length or slightly longer than the total combined length of the third, fourth and fifth segments (5.5 % CL). The e-seta is similar in length (36 % CL) to the limb. Its armature is unique in that it consists of a single row of 7 – 9 hyaline, flanged spines, in contrast to the double row seen in all other Metaconchoeciini species. The length of the d-seta is also exceptional for the tribe in being longer (1.2 x) than the e-seta. Second antenna. The protopodite is 46 % CL. The first segment of the exopodite is relatively slim, about 35 % the length of the protopodite. The h – j sensory setae on the endopodite are 50 – 60 % of the length of the g-seta. The g-seta is 50 – 62 % of the length of the protopodite, and 73 – 74 % of the exopodite, and 1.7 – 1.8 x the first endopodite segment. Both the f- and g-setae are more or less parallel-sided with either rounded or pointed tips. The h-seta is simple and undivided. The c- and d-setae are stout and quite long, but the e-seta is minute. The hook appendages on the endopodites are curved and terminally rounded. They are similar in size and shape, with large, stout distal arms that are swollen centrally. Mandible (Fig. 2 L). The exopodite is reduced to a minute triangular protuberance that carries a long, slim, seta with long setules. The coxale is relatively short and about two-thirds the length of the endopodite. The first segment of the endopodite has a finely spinose, subterminal seta on its dorsal surface and two setae on its inner ventral surface, one longer than the endopodite, the other half its length. The longest terminal seta of the endopodite is 22 % CL and nearly 90 % of the endopodite itself. Copulatory appendage. The appendage is large, being 45 – 48 % CL. It is highly curved distally and tapers terminally. The tip characteristically carries an offset triangular plate. The appendage is broadest near or slightly beyond midlength. There are 2 – 4 oblique muscle bands. Females. Carapace. The length range is 0.90 – 1.12 mm (mean 1.01 ± 0.041 mm). The carapace is short and more elongate than in the male (42 % CL); the maximum height occurs at or just behind midlength. The breadth is 48 % CL. The LAG opens 12 – 15 % CL behind the tip of the rostrum and 3 % CL posterior to the anterior edge of the hinge. The RAG opens on a small protuberance on the posterior margin 12 – 17 % CH below the posterior dorsal corner. The rostrum is less developed than in the male, 5 – 8 % CL. As in the male, there is no sculpture on the carapace. Frontal organ. The shaft is clearly divided from the capitulum by a septum. The shaft is 18 % CL. The capitulum is 12 % CL; it is straight and narrow with a rounded or bluntly pointed tip and is sparsely spinous around the flanks, especially at midlength. Its thickness is similar to or slightly larger than that of the shaft. The whole frontal organ is 29 – 30 % CL, and is 1.5 x the length of the A 1. First antenna. The limb segments are fused, and their total length is 20 – 21 % CL. There is no dorsal seta. The aseta is simple and undivided. The e-seta is 1 – 1.5 x the length of the limb and 1.3 – 1.8 x the sensory setae. Distal to the ends of the sensory setae, its trailing edge is armed with strong, long spines. Second antenna. The protopodite is 42 – 43 % CL. The first exopodite segment is 20 % CL and relatively thin; segments 2 – 9 that carry the swimming setae are 44 % of the first segment. The terminal setae on the endopodite are thin, and disparate in length, (f-seta 20 % CL, g-seta 22.5 % CL, and the h- to j-setae 19 % CL). They are either parallel-sided or very slightly tapered, with pointed tips. Mandible. The structure of this limb is similar to that of the male.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	distribution	Distribution. Endemic to the Southern Ocean where it occurs over a wide latitudinal range from 49 ºS to 78 ºS in all sectors (Müller 1906 a, 1906 c, 1908; Skogsberg 1920; Hillman 1967; Deevey 1974, 1978 a, 1982 a, 1983; Angel 1981 b, Hopkins 1985; Hopkins & Torres 1989; Kock 1992; Naldi et al. 1992; Benassi et al. 1992; Blachowiak-Samolyk 1999, 2001; Blachowiak-Samolyk & Angel 2003, 2007: Blachowiak-Samolyk & Zmijewska 1995, 1997; Blachowiak-Samolyk & Osowiecki 2002; Drapun 2004). Its overall depth range is reported to be 0 – 3248 m. However, the deeper records are all from nets fished open. Stratified sampling in the austral summer has shown it generally occurs between 200 – 500 m and occasionally as shallow as 100 m. The possibility that it undertakes seasonal migration into deep water in winter can not be ruled out. CLAUSOECIA Chavtur & Angel n. gen. Synonymy 1906 a Conchoecia ‘ rotundata’ group — Müller, p. 79 (part). 1955 Metaconchoecia — Howe, p. 118 (part). 1968 Conchoecia rotundata group — Deevey, p. 50 (part). 1973 Metaconchoecia — Poulsen, p. 70 (part). 1980 Conchoecia rotundata group — Deevey & Brooks, p. 85 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 141 (part), 159 (part). 1982 a Conchoecia rotundata group — Deevey, p. 148 (part). 1986 Metaconchoecia — Kempf, p. 486 (part). 1992 Metaconchoecia — Kock, p 68 (part). 1993 Conchoecia — Angel, p. 204 (part). 1999 Metaconchoecia — Angel, Figs 9.58 – 76 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	etymology	Etymology. The name is derived from “ Claus ” in honour of that early doyen of halocyprid taxonomy Carl Claus, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	type_taxon	Type species. Conchoecia pusilla (Müller, 1906 a). Composition. The genus is currently monospecific containing just C. pusilla (Müller, 1906 a) but significant size differences have been reported between different populations. Müller 1906 a, for example, reported a small form, so probably there are cryptic species awaiting recognition.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	diagnosis	Differential diagnosis. Small, deep mesopelagic species <1 mm in length with the maximum height posterior to midlength. The LAG opens 12 to 15 % CL posterior to the tip of the rostrum. The RAG opens on the apex of an angle in the posterior margin 10 to 12 % CL behind the posterior margin of the hinge. The carapace has a slight anterior taper and the flanks curve smoothly. The male A 1 e-seta armature consists of 20 to 25 slim spines that are paired distally and become alternate proximally.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	description	Description. Males. Carapace: The length range is 0.66 – 1.00 mm. Müller (1906 a) in his original description, described the males as being typically 0.85 – 0.95 mm in length, but also reported a small ‘ form’ in which the males are 0.75 – 0.8 mm. These smaller forms are yet to be investigated. The carapace is somewhat elongate, with a maximum height of 45 – 50 % CL, located close to midlength. The dorsal margin is nearly straight, and the ventral margin is slightly concave, so that the anterior and posterior halves of the carapace are very similar. The maximum breadth of 47 % CL is slightly anterior to midlength, and in many specimens it exceeds the height. Lrost is 9.3 % CL, but LC 3 is 7 % CL. The LAG opens 14 – 15 % CL posterior to the tip of the rostrum, and nearly 6 % CL behind the posterior margin of the incisure. The RAG opens at the apex of a distinct angle in the posterior margin 12.5 % CL behind to the posterior end of the hinge and 11 – 15 % CH. The posterior margin dorsal to the RAG is straight and forms an obtuse angle with the dorsal margin at the posterior margin of the hinge. There is no surface ornamentation. Frontal organ: The shaft is similar in length (33.4 % CL) to the A 1 limb, and is separated from the long (20.1 % CL) capitulum by a suture. The capitulum is long, narrow, down-turned and bare. The basal two-thirds of its length is almost straight-sided, but distally the dorsal margin is convex, so the capitulum broadens towards its rounded end. First antenna: The limb is segmented, and the first segment is slightly smaller than the second. The dorsal seta that locks the shaft of the frontal organ to the second segment of the limb is located 14.8 % CL from the base of the capitulum. The a-seta is simple, undivided and quite long (27.8 % CL). It extends well beyond the suture between the first two segments. It is S-shaped but unswollen at its base. The c-seta is short (6.2 % CL), and shorter than the combined length of the third, fourth and fifth segments. The e-seta is 39 % CL, only slightly longer than the b-seta (38 % CL) and the d-seta (35.5 % CL). The e-seta armature consists of 20 – 25 broad-based, slightly curved, pointed spines, which are paired distally, but become alternate proximally. Second antenna: The protopodite is relatively long (about 58 % CL). The first exopodite segment is 20 % CL and has a terminal seta that curls around the base of the second segment. Together, segments 2 – 9 are 45 % the length of the first segment, so the whole exopodite is 60 – 65 % the length of the protopodite. On the endopodite, the g-seta is 43 – 44 % CL, and the f-seta is 36 % CL; both these setae are slightly flattened terminally and have pointed ends. The sensory h-, i-, and j-setae are simple, thin-walled and similar in length (14 – 15 % CL). The hook appendages are slightly curved and end in oblique points with subterminal ridging. The left hook is slightly smaller and straighter. Mandible (Fig. 2 E): Dorsally the first endopodite segment has a subterminal, short, finely seta with long setules. On its inner ventral face this segment has a single, moderately long seta that does not quite reach to the end of the limb. As usual there are seven terminal seta on the third segment; the longest is 22 % CL and similar in length to the limb itself. The exopodite consists of a short process armed with short seta with long setules, which is quite stout at its base but rapidly becomes quite slim. The coxale is short and about half the length of the endopodite. Maxilla: The setation of the endopodite is consistent with all the other species in the tribe. On the basal segment there are four anterior setae, a single lateral seta and three posterior setae. The terminal segment carries three hook setae and two lateral setae. Fifth limb: The epipodial appendage has three groups of 4 + 4 + 4 setae. The basale generally has ventrally a group of 5 basal setae and a further 2 setae distally. This segment has no lateral setae, but occasional specimens do appear to have three lateral setae but correspondingly fewer ventral setae. The orientation of the limb on the slide probably determines whether these setae appear to be lateral or ventral. Dorsally, there is a long subterminal seta, but no seta with setules was seen in the specimens dissected. Drapun (personal communication) has observed a dorsal seta with long setules. The first endopodite segment has two medial ventral setae and one medial dorsal seta. All three of these setae are quite long and extend well beyond the end of the segment. The terminal setae have length ratios of 100: 95: 50; it is unusual for the dorsal terminal seta to be the longest. The longest seta is 10.2 % CL and 70 % of the limb. Sixth limb: The setae on the epipodial appendage are as usual arranged in three groups of? 6 + 5 + 5. The basale has 3 or 4 ventral setae, 0 to 2 lateral setae and dorsally a single seta with long setules. The first endopodite segment has a single short, medial seta ventrally but no dorsal seta. The second segment has a single short medial seta on both the dorsal and the ventral sides. The three long terminal setae are similar in length (about 38 % CL), and> 120 % the length of the limb. Caudal furca: There are the usual eight pairs of spines on the caudal furca, the longest of which is 15.5 % CL. There is an unpaired seta posterior to the paired spines. Copulatory appendage: The length of the appendage is 34 % CL. The posterior edge is almost straight, and the ventral edge is slightly convex in its distal half. The end is bluntly rounded, and there are four or five oblique muscles. Females. Carapace: The length range is 0.7 – 1.0 mm. The carapace is elongate and tapers very slightly, although the maximum height of 45 – 53 % CL is located close to midlength. In ventral aspect the carapace is slim and spindle-shaped; its maximum width of 40 % CL length is anterior to midlength, and the flanks are smoothly curved. The rostrum is well developed (Lrost = 11 % CL, LC 3 = 6 % CL). As in the male the LAG opens 11 – 16 % CL posterior to the tip of the rostrum. The RAG opens at a well-marked angle in the posterior margin 10 % CL behind the posterior end of the hinge and 6 – 8 % CL below the hinge-line. Above the gland opening the posterior margin is straight forming an obtuse angle with the dorsal edge; below the RAG opening it curves smoothly into the ventral margin. The carapace has no sculpture. Frontal organ: The frontal organ is fused and its overall length is 30 % CL, and is nearly double the length of the A 1 limb. The capitulum is long, straight, ventrally hirsute, and very slightly expanded distally. It has a bluntly rounded tip. First antenna: The limb is fused with no obvious segmentation, 15 % CL in length. There is no dorsal seta. The sensory a-, b-, c- and d-setae are simple and thin-walled, and are 12 % CL in length. The e-seta is about double the length of the sensory setae (24.5 % CL) and 1.6 x the length of the limb. Distal to the sensory seta, the e-seta is lined with short fine spines along its trailing edge and also has a few longer, thicker spines along its leading edge. Second antenna: The protopodite is 43 % CL, and the first exopodite segment is 20 – 21 % CL and relatively slim. The distal segments of the exopodite that carry the swimming setae together are about 43 % the length of the first segment, making the overall length of the exopodite 65 – 70 % of the protopodite. The terminal setae on the endopodite are simple and unflattened. The g-seta is 20 % CL and the other four setae are 18 % CL. Mandible: Similar to that of the male. Fifth limb: The epipodial appendage carries three groups of 4 setae. The basale has 3 + 2 ventral setae, two lateral setae, and dorsally a further two setae, one long and bare and the other shorter with long setules. The first endopodite segment has a pair of medial ventral setae, one extending to the end of the segment, the other a little further. There is also a single medial dorsal seta, which extends beyond the end of the segment. The length ratios of terminal seta on the second segment are 100: 95: 55. So as in the male, the dorsal terminal seta is the longest of the three, and is 8.8 % CL and 60 % the length of the limb. Sixth limb: There are the usual three groups of epipodial setae (6 + 5 + 5 ventral). Ventrally the basale has 2 bare and 2 setae with setules. There is no lateral seta, but there is a single, long, dorsal seta with setules (Drapun observes two dorsal setae with long setules in specimens from the Indian Ocean, pers. comm.). The first segment has a single medial ventral seta. Medially the second segment has both a dorsal seta and a ventral seta; both are quite long and extend beyond the end of the segment. The length ratios of the three terminal claw setae are 80: 100: 65. The longest central seta is nearly 11 % CL and 56 % of the limb. Caudal furca: There are eight pairs of claw setae and an unpaired, slim seta at the dorsal margin of the two lamellae. The longest claw seta is 14 – 15 % CL.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	discussion	Comments. The original description of Conchoecia pusilla (Müller, 1906 a) was based on material collected from both the Atlantic and the Indian Oceans, in which Müller reported collecting a small form var. minor from near the equator in the Indian Ocean. Our material collected from near the equator (0 °, 23 ° W) in the Atlantic is similar in size to his small form, whereas the material collected from the vicinity of the Azores Front (35 ° N, 30 ° W) was similar in size to Müller’s typical form. Another, even smaller form has been collected from depths> 2000 m near Bermuda (32 ° N 65 ° W). Another collection from the Celebes Sea contained specimens that are clearly related to C. pusilla, but look different from the typical Atlantic forms. When the taxonomy of these various forms is sorted out, the genus will probably consist of several species.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3BFFFA6FDDFF72A310F801.taxon	distribution	Distribution. Atlantic Ocean: between 60 ºN and 3 ºS (Müller 1906 a; Angel & Fasham 1975; Angel 1977, 1979, 1981 b; Deevey 1968; 1978 b, 1982 a; Ellis 1985) and in the area 34 º – 36 ºS and 17 º – 18 ºE (Müller 1906 a). Indian Ocean: from 9 ºN to 23 ºS (Müller 1906 a; Leveau 1967; Hanai et al. 1980). Pacific Ocean: in the area bounded by 28 – 29 ºS and 177 º – 179 ºE (Poulsen 1973), in the China Seas (Chen et al. 1983; Chen & Lin 1994, 1995), and to south of 36 ºS (Deevey 1983). Southern Ocean: recorded from 64 ºS, 85 ºE in the Indian Ocean sector (Müller 1908) and from 44 ºS, 178 ° W and 45 ºS, 160 ° E in the Pacific sector (Deevey 1982 a). The overall reported depth range is 0 – 2500 m, but depth stratified samples collected in the North Atlantic show the species is mostly restricted to depths of 700 – 1500 m. Comparisons. Species attributed to Clausoecia and Austrinoecia are very similar in their external appearances. The main characters that discriminate these two genera are summarized in Table 7 and Appendices 1 – 3, and are in part illustrated in Figure 2.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	description	1906 a Conchoecia ‘ rotundata’ group — Müller, p. 79 (part). 1953 Conchoecia — Iles, p. 270 (part). 1955 Metaconchoecia — Howe, p. 118 (part). 1970 Conchoecia — Deevey, p. 810 (part). 1974 Conchoecia — Deevey, p. 364 (part). 1973 Metaconchoecia — Poulsen, p. 70 (part). 1980 Conchoecia rotundata group — Deevey & Brooks, p. 85 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 141 (part), 159 (part). 1981 a Conchoecia — Angel, p. 47 (part). 1982 a Conchoecia — Deevey, p. 484 (part). 1986 Metaconchoecia — Kempf, p. 498 (part). 1992 Metaconchoecia — Kock, p. 68 (part). 1999 Metaconchoecia — Angel, Figs 9.58 – 76 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	etymology	Etymology. The name is derived from Latin nasus, - i, meaning nose, since the LAG opens on the rostrum, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	type_taxon	Type species. Conchoecia nasotuberculata (Müller, 1906 a). Composition. This genus is monospecific, Nasoecia nasotuberculata (Müller, 1906 a) being the sole species.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	diagnosis	Differential diagnosis. The species is small (0.74 – 0.88 mm) and globose (CH is 52 − 62 % CL). The LAG opens on the rostrum, anterior to the anterior end of the carapace hinge. The RAG opens on the posterior margin about 10 % CH below the hingeline. In females there is a large lateral tubercle on each valve close to the posterior dorsal corner. In males similar lateral tubercles are present, but are much smaller. In some specimens there is a faint concentric pattern of sculpturing. The A 1 e-seta armature in males consists of 10 − 12 pairs of slim spines.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	description	Description. Males. Carapace: The length range is 0.74 – 0.90 mm. The carapace is rather globose, being short and relatively high, with a maximum height of 52 – 58 % CL. The breadth is also ≥ 50 % CL. Laterally on each valve close to the posterior dorsal corner there is a weakly developed tubercle (the tubercles are much more obvious features in females). In ventral aspect the curve of the carapace is indented just posterior to the shoulder vaults. This character immediately distinguishes this species from all the other small, globose species other than K. kyrtophora. Lrost is 10 % CL, and LC 3 is 9.5 % CL. The LAG opens on the rostrum only 2 – 6 % CL behind the tip (variously reported as 2.2 % (Angel 1981 a), 5.2 % (Müller 1906 a) and 6.1 % (Gooday 1981 )). It opens anterior to the anterior hinge between the valves of the carapace; an attribute unknown in the other genera of Metaconchoeciini. The RAG opens on the posterior margin 8 – 13 % CH below the dorsal margin. The surface of the carapace often has weak concentric striations. Frontal organ: The shaft is segmented and its length is 38 % CL, which is the same as the A 1 limb. The capitulum is long (16 – 17 % CL), broad, slightly concave, finely spinose, and down-turned, with a rounded tip. The shaft is a little shorter than the A 1, but the capitulum extends well beyond its end. First antenna: The limb (37 – 38 % CL) is similar in length to the shaft of the frontal organ and just over double that of the capitulum. Its segmentation is clear, with the first segment being slightly shorter than the second. The aseta is simple, S – shaped and slightly swollen near its base. It is quite long (21 – 22 % CL) and extends beyond the suture between the first two segments. The c-seta is short (4 – 5 % CL), but only slightly shorter than the combined lengths of the third, fourth and fifth segments. The armature of the e-seta consists of 12 – 14 pairs of short, thin spines that lie parallel with the seta, pointing basally. The e-seta is 52 % CL and nearly 1.5 x times the length of the limb; it is also slightly longer than both the d-seta (46 % CL) and the b-seta (44 % CL). Second antenna: The protopodite is quite long (50 % CL). The exopodite is short, about 55 – 58 % the length of the protopodite, and is of medium thickness. The a- and b- setae are subequal, slightly curved and finely spinose. The c- and d-setae are slim and short, and the e-seta is minute. The g- and f-setae are 46 % CL and 41 % CL respectively, and may be slightly flattened terminally. The sensory setae (h-, i-, and j-setae) are 16 % CL, and just over a third the length of the g-seta. The hook appendages are slim, curved, and terminally rounded with some traces of subterminal ridging. The left hook is the smaller, and its distal arm is only slightly curved. Mandible (Fig. 2 J): The first endopodite segment has a subterminal dorsal seta that is either finely bare or with fine setules, and on its inner ventral margin it has two moderately long setae both of which extend to the end of the limb. The longest of the seven terminal setae on the third segment is 22 % CL and is similar in the length to the limb. The exopodite process is quite large and bears a short, relatively slim, seta with long setules. The coxale is long and is 80 % of the length of the endopodite. Maxilla: The first segment of the endopodite has 4 anterior setae, a lateral seta, three posterior setae, and terminally there are three small spines. The end segment has the usual three terminal hook setae and two slim, subterminal lateral setae. Fifth limb: The epipodial appendage carries three groups of four setae. The basale has two pairs of setae on the ventral edge, a single lateral seta, and dorsally a long bare seta that reaches to the end of the limb, and a shorter seta with long setules. Drapun (pers. comm.) observes an additional pair of lateral setae in specimens from the Indian Ocean. The limbs of both specimens dissected were somewhat damaged, and this probably account for the apparent disparities between the setation of the female and male limbs. The first endopodite segment has two medial ventral setae and a single medial dorsal seta. All three setae extend to just beyond the end of the segment. The terminal claw setae on the last segment have length ratios of 75: 100: 65, the longest being 8.3 % CL and 80 % of the limb. Sixth limb: The epipodial appendage carries three groups of plumose setae (6 dorsal + 5 + 5). The basale has two pairs of setae on the ventral surface, one lateral seta, but apparently no dorsal seta (i. e. no vestige of an exopodite). The first segment has just a single, short, ventral seta, whereas the second segment has a very short medial seta on both the dorsal and ventral surfaces. The three terminal setae on the third segment are subequal and long (44.5 % CL and 125 % the limb itself). All three terminal setae have long setules along the distal one-third of their lengths. Copulatory appendage: Its breadth is 34 – 35 % of its length. It is straight, parallel-sided and has a rounded tip; it has three oblique muscle bands. Caudal furca: The caudal furca has the usual eight pairs of hook spines that diminish in size posteriorly; the first and longest pair of claws is 15 % CL. In some specimens there is an unpaired seta at the back of the furca between the two lamellae, however, Angel 1981 a (his fig 2 G) did not illustrate the seta nor does it appear in Arabian Sea specimens (Drapun pers. comm.). Females. Carapace: The length range is 0.74 – 0.90 mm. The carapace is rather globose; the maximum height of 53 – 63 % CL is in the posterior half. In ventral aspect the flanks curve smoothly with the maximum width a little anterior to midlength. The most striking features are the large lateral tubercles that are situated close to the posterior dorsal corner. (Note: The caption to Müller’s original (1906 a) drawing (Pl. 17, fig. 2) shows these tubercles, but is erroneously attributed to Conchoecia kyrtophora). The rostrum and incisure are similar to those of the male. The opening of the LAG is uniquely placed on the rostrum, 0.5 – 8 % CL behind its tip [0.6 % (Angel 1981), 4.2 % (Poulsen 1973), 4.2 % (Deevey 1970) 6.8 % (Chavtur unpublished), 8.0 % (Deevey 1974)] but always anterior to the anterior end of the hinge. The RAG opens on the posterior margin 11 – 17 % CH below the dorsal margin (i. e. 5 – 8 % CL). As in the male, there may be weak, concentric sculpturing. Frontal organ: The frontal organ is fused, but the straight capitulum is slightly broader than the shaft, terminally rounded, and finely spinose along its ventral margin. The overall length of the frontal organ is 30 – 32 % CL, i. e. 1.5 – 2 x the length of the limb of the first antenna and similar in length to the e-seta. First antenna: The segments are fused, and the overall length is 16 – 18 % CL. The sensory setae (a- to d-) are simple and quite short (13 – 16 % CL). The length of the e-seta is about 32 % CL, i. e. 1.7 – 2.3 x the length of the limb and 2 – 2.5 x the sensory setae. Distal to the ends of the sensory seta, the e-seta carries minute fine spines along its trailing edge. Second antenna: The protopodite is 42 – 44 % CL. The first exopodite segment exopodite is 17 – 19 % CL and of medium thickness. It appears to lack the terminal seta that is present on the male exopodite. Segments 2 – 9, which carry the swimming setae, are about half the length of the first segment, so overall the exopodite is quite short and is only around 60 – 65 % the length of the protopodite. The terminal setae on the endopodite are subequal and unflattened; their lengths are 19 – 23 % CL (i. e. 50 % of the protopodite). Mandible: The structure of this limb is similar to that of the male. Fifth limb: The epipodial appendage has three groups of four setae. The basale has five ventral setae, a group of three near its base and a more distal pair; it has two lateral setae, and dorsally a seta with long setules and a long subterminal seta that extends to the end of the limb. The first endopodite segment has a medial pair of ventral setae and a single medial dorsal seta; all these setae extend to the end of the segment. The end segment carries the usual three terminal setae (dorsal to ventral length ratios 90: 100: 50). The longest is 7.5 % CL and 75 % of the limb. Sixth limb: The epipodial appendage has three groups of setae (6 dorsal + 5 + 5). The basale has four or five ventral setae, a single lateral seta, but no dorsal seta was seen. The first segment has only a ventral medial seta. The second segment has a single medial seta on both its dorsal and ventral margins; both of these setae are quite long and extend to the end of the segment. The lengths of the terminal three setae have ratios of 75: 100: 50 (ventral). The longest seta is 10 % CL and about 60 % the length of the limb. Comparisons. This genus is most closely resembles Kyrtoecia (see below). Some of the characters that discriminate between these two genera are summarized in Table 8 and Appendices 1 – 3 and illustrated in Figure 2.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	distribution	Distribution. Atlantic Ocean and Mediterranean Sea: occurs between 18 ºN and 40 ºS (Müller 1906 a, 1908; Iles 1953, Deevey 1970, 1982 b; Angel 1981 a; 1981 b, Gooday 1981), and one specimen has been collected from 62 ºN, 17 ºW (Chavtur, unpublished). Indian Ocean: latitudes 4 ºN to 3 ºS (Müller 1906 a). Pacific Ocean and Pacific sector of the Southern Ocean: latitudes 22 º to 54 ºS (Poulsen 1973; Deevey 1982 a, 1983) and from one station situated at 37 ºS, 144 ºE (Chavtur 1977 a). Overall its reported depth range is 0 – 2500 m. However, the maximum depth is a sampling artifact resulting from fishing non-closing nets as stratified sampling in the North Atlantic shows that it is almost entirely restricted to depths of 100 – 400 m. KYRTOECIA Chavtur & Angel n. gen. Synonymy 1906 a Conchoecia ‘ rotundata’ group — Müller, p. 79 (part). 1955. Metaconchoecia — Howe, p. 118 (part). 1968 Rotundata group — Deevey, p. 50 (part). 1970 Conchoecia — Deevey, p. 810 (part). 1973 Metaconchoecia — Poulsen, p. 70 (part). 1979 Metaconchoecia — Martens, p. 352. 1981 Conchoecia skogsbergi species complex — Gooday, p. 159 (part). 1981 a Conchoecia — Angel, p. 53 (part). 1986 Metaconchoecia — Kempf, p. 149 (part). 1992 Metaconchoecia — Kock, p. 68 (part). 1999. Metaconchoecia — Angel, Figs 9.58 – 76 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	etymology	Etymology. The name is derived from Greek κʋρτοσ meaning “ arched ”, “ curved ”, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning house, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	type_taxon	Type species. Conchoecia kyrtophora Müller, 1906 a. Composition. This genus is monospecific, and includes just Kyrtoecia kyrtophora (Müller, 1906 a)	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	diagnosis	Differential diagnosis. Small, globose species (carapace length 0.76 − 0.93 mm). LAG opens 6.0 % CL behind the tip of the rostrum and posterior to the anterior edge of the hinge. The RAG opens close to the PDC. In its ventral aspect, the lateral margin of the carapace is constricted just behind the shoulder vaults. The armature of the male A 1 e-seta consists of 16 – 22 square ended spines set at right angles to the seta. These spines are paired distally, but proximally they become alternate.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	description	Description. Males. Carapace: The length range is 0.75 – 0.90 mm. The carapace is very short and rather globose; its maximum height of 51 – 59 % CL is just posterior to midlength. The breadth is usually slightly less than the height. In ventral aspect the carapace is characteristically constricted posterior to the shoulder vaults; the maximum width is anterior to midlength across the shoulder vaults. Lrost is 6 % CL, but LC 3 is> 7 % CL. The LAG opens just behind the rostrum; posterior to the anterior margin of the hinge, but about level with the hindmost margin of the incisure. The RAG opens almost level with the posterior end of the hinge, and just below the hinge-line, 3 – 6 % CH below the posterior margin. The surface of the carapace is sculptured with very faint concentric striae. Frontal organ: The capitulum is clearly separated from the shaft, which is quite long (35 – 37 % CL). The capitulum is also long (19 – 22 % CL), narrow, slightly concave, and terminally rounded. It has fine spinules along its ventral margin. The shaft is slightly longer than the A 1 limb, so overall the frontal organ is considerably longer than the A 1 limb. First antenna: The limb is clearly segmented, with the first segment being slightly shorter than the second. Its overall length is 35 – 38 % CL, about twice the length of the capitulum. The a-seta is S-shaped and unswollen at its base and has no side branch. It is quite long (25 – 26 % CL) and extends well beyond the base of the second segment. The c-seta is short (5 % CL), and shorter than or subequal to the combined lengths of the third, fourth and fifth segments. The e-seta is quite long (47 – 48 % CL), longer than both the d-seta (39 % CL) and b-seta (37 % CL). Its armature is unique in the Metaconchoeciini, in that it consists of 16 – 22 square-ended pegs that are set at right angles to the seta. Distally they are paired, and become alternate proximally. Second antenna: The protopodite is 50 % CL. The first segment of the exopodite is quite slim (20 % CL) and appears to lack a terminal seta. Overall, the other distal exopodite segments are slightly less than half the length of the first segment. On the endopodite the g-seta is nearly 50 % CL, and the f-seta is 43 – 45 % CL; both these seta are unflattened and have sharply pointed tips. The sensory setae (h – j) are subequal and 14 – 15 % CL. Both hook appendages are curved and then curve again near their ends, which are ridged with bifid or even trifid points; the left hook is, as usual, the smaller. Mandible (Fig. 2 H): The endopodite has a subterminal dorsal seta, and a single inner ventral seta that nearly reaches to the end of the limb. The second segment has three dorsal (1 long) and 2 ventral (1 long) setae. There are the usual seven terminal setae on the third segment. The longest claw seta is> 75 % the length of the limb and 20 % CL. The exopodite consists of just a short, slim, seta with long setules, and there is no process. The coxale is short and about half the length of the endopodite. Maxilla: The first segment of the endopodite has four anterior setae, a single lateral seta, and three posterior setae; a pattern that is typical of the tribe. There are up to seven small spines on the outer distal margin of the first segment. The end segment carries the usual three terminal spines and two subterminal setae. Fifth limb: The epipodial appendage has three groups of 4 setae. Proximally the basale has a group of three ventral setae and distally two more setae. It lacks a lateral seta, but dorsally it carries two, one with long fine setules the other a long and subterminal, which is the vestigial exopodite. The first endopodite segment has two ventral and a single dorsal seta, all of which extend to the end of the segment. The terminal segment has three terminal setae (dorsal to ventral length ratios 90: 100: 50), the longest of which is 8 % CL and 65 % of the length of the limb. Sixth limb: The epipodial appendage has three groups of 7 + 5 +? 5 setae. The basale has 4 or 5 ventral setae, possibly a single lateral seta, and a short dorsal seta. The first segment has a single short ventral seta, but no dorsal seta. The second segment has a ventral medial seta that reaches halfway to the end of the segment, and a much shorter dorsal seta. The three terminal setae on the third segment are subequal, 45 % CL and 150 % of the length of the limb. They all carry long setules on the distal third. Caudal furca: The longest of the eight pairs of hook spines is 18 % CL. Copulatory appendage: The length of the appendage is 33 – 35 % CL. It is almost straight and parallel-sided. The end is obtusely angled. It has 2 – 3 oblique muscle bands. Females. Carapace. The length range is 0.76 – 0.93 mm. It is short and relatively high with the maximum height of 54 – 59 % CL located just posterior to midlength. Viewed ventrally, the flanks are constricted behind the shoulder vaults; this character readily distinguishes females of this species from N. nasotuberculata. Lrost is short (6 – 8 % CL) and LC 3 is slightly longer (~ 8.7 % CL). As in the male, the LAG opens just behind the hinge. The RAG opens 4 % CL posterior to the posterior end of the hinge and 4 % CH below the hinge line. As in the male there is faint concentric sculpturing. Frontal organ: The frontal organ is fused with an overall length of 29 – 32 % CL and is substantially longer than the A 1 limb. The capitulum is almost straight and similar in thickness to the shaft. It is finely spinose along its ventral margin and along the distal half of the dorsal margin. The end is rounded. First antenna: The limb segments are fused, and its overall length is 17 – 21 % CL. There is no dorsal seta. The sensory setae (a- to d-) are thin-walled and simple (14 – 17 % CL). The e-seta is 26 – 27 % CL, longer than the limb and much longer than the sensory seta. Along its trailing edge, distal to the ends of the sensory setae, it is armed with minute spines. Second antenna: The protopodite is 46 – 47 % CL. The first exopodite segment is 17 % CL, about double the combined lengths of the three distal exopodite segments; and it lacks a terminal seta. On the endopodite the terminal setae are simple, unflattened, and thick with rounded ends. The longest g-seta is 21 – 22 % CL, and the other setae are subequal at 18 – 19 % CL. Mandible: Similar to that of the male. Fifth limb: The epipodial appendage has three groups (4 + 4 (sometimes 5) + 4) of setae. The basale has groups of, 3 + 2 setae ventrally, 2 + 2 setae laterally, and dorsally two setae; one moderately long with long setules, the other bare, subterminal, and long extending to the end of the limb. The first endopodite segment has medially two ventral setae and a single dorsal seta. The terminal setae usually have length ratios of 90: 100: 50. The longest seta is 7.4 – 7.7 % CL and 65 – 70 % the length of the limb. Sixth limb: The epipodial appendage has three groups of 5 + 5 + 5 setae. The basale has ventrally 4 – 6 ventral setae arranged in pairs, laterally no seta, and dorsally two setae; one carries long setules and is shorter than the other long bare seta, which barely reached the tip of the limb and so is relatively shorter than in other Metaconchoeciinae species. The first endopodite segment has a single ventral seta and usually a single dorsal seta. The second segment also has a single medial ventral and a longer medial dorsal seta; both these setae extend beyond the end of the segment. The terminal setae have length ratios of 75: 100: 65. The longest of these setae was 9.5 – 10 % CL and slightly less than 60 % the length of the limb. Comparisons. This monospecific genus is most similar to Nasoecia. The characters that most readily discriminate between these two genera are summarized in Table 8, Appendices 1 – 3, and illustrated in Figure 2.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC3FFFE76FDDF9ECA068FE19.taxon	distribution	Distribution. In the Atlantic Ocean between 18 ºN and 40 ºS (Müller 1906 a, 1908; Deevey 1974; Angel 1979, 1981 a, 1981 b; Angel & Fasham 1975; Gooday 1981). Indian Ocean: reported from 7 ºN to 10 ºS (Müller 1906 a; Hanai et al. 1980; George & Nair 1980). In the Pacific Ocean it has been reported from the northwest sector between 6 ºN and 13 ° N (Chavtur, unpublished), from the southwest sector around 30 ºS, at 71 ° to 73 ° W (Martens 1979), from the southeast sector at two stations 22 ° S, 166 ° E and 28 ° S, 173 ° W (Poulsen 1973). So far there have been no reports from the northeastern sector. Its overall depth range is reported to be 0 – 2500 m, but stratified sampling shows it to be almost entirely restricted to subthermocline depths of 50 – 200 m (Angel, Blachiowiak-Samolyk and Chavtur 2008).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	description	1894 Conchoecia rotundata — Müller, p. 229 (part). 1906 a Conchoecia rotundata group — Müller, p. 83 (part). 1909 Conchoecia rotundata group — Fowler, (part). 1953 Conchoecia — Iles, p. 271 (part). 1968 Conchoecia — Deevey, p. 55 (part). 1973 Metaconchoecia — Poulsen, p. 74 (part). 1974 Conchoecia — Deevey, p. 364 (part). 1978 Conchoecia — Deevey, p. 53 (part). 1979 Metaconchoecia — Martens, p. 352 (part). 1981 Conchoecia skogsbergi species complex — Gooday, p. 141 (part). 1981 Conchoecia — Angel, p. 560 (part). 1986 Metaconchoecia — Kempf, p. 486 (part). 1999 Metaconchoecia — Angel, figs 9.58 – 76 (part).	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	etymology	Etymology. The name is derived from the Latin adjective “ rotundus, - a, - um ” meaning round, and “ - oecia ” derived from the Greek word “ οƖκοσ ” meaning “ house ”, from which the terms ecology and economy have been derived, and is the ending that has become standard for Conchoeciinae genera.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	type_taxon	Type species. Conchoecia teretivalvata Iles, 1953. Composition. The genus consists of a single species Rotundoecia teretivalvata (Iles, 1953)	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	diagnosis	Differential diagnosis. Small globose species 0.78 – 1.15 mm, with a height of 52 – 60 % CL and a width of 42 – 48 % CL. The ventral margin curves smoothly into the posterior margin, and the flanks also curve smoothly from the rostrum to the posterior margin. The carapace lacks sculpturing. The rostrum is quite small (8 % CL) and the incisure is quite shallow. The LAG opens 11 to 12 % CL behind the tip of the rostrum. The RAG opens on the posterior margin, nearly adjacent to the posterior end of the hinge. The male A 1 e-seta armature consists of 9 to 11 pairs of slim spines.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	description	Description. Males. Carapace: The length range in the Atlantic is 0.76 – 0.92 mm, but larger specimens (up to 1.15 mm) have been reported both in the Southern Ocean (Deevey 1974) and in the S. E. Pacific off Chile (Martens 1979). The maximum height, 50 – 55 % CL is located well posterior to midlength, so the carapace tapers anteriorly. In the ventral aspect, the flanks curve smoothly with the maximum breadth of 48 % CL at midlength. Lrost is 8 % CL anterior, and LC 3 is 7 % CL. Ventrally the incisure is quite shallow, and the anterior margin of the carapace hardly projects beyond the inner margin of the incisure. The LAG opens 10 – 13 % CL behind the tip of the rostrum, and 3 % CL behind the anterior end of the hinge; it is also posterior to the inner margin of the incisure. The RAG opens almost adjacent to the posterior end of the hinge and close to the posterior dorsal corner. There is no visible surface ornamentation. Frontal organ: There is a clear division between shaft and capitulum. The shaft is 32 % CL, and slightly shorter than the A 1 limb; it is segmented at midlength just posterior to where the locking dorsal seta from the A 1 entwines around the shaft. The spinose capitulum (12.5 % CL) is slightly down-turned, and similar in shape to those of Metaconchoecia species. The overall length of the frontal organ is 43 – 44 % CL, so the tip of the capitulum just extends beyond the end of the A 1 limb. First antenna: The limb is clearly segmented, with the first segment being three-quarters the length of the second. Its overall length is 37 – 38 % CL. The a-seta is sinuate and slightly swollen near its base. It is long (26 % CL), reaching well beyond the suture between the first and second A 1 segments. The c-seta is very short (4 % CL). The eseta is 55 % CL and is longer than both the b-seta (48 % CL) and the d-seta (50 – 51 % CL). Its armature consists of 9 – 11 pairs of long, thin spines, which distally are closely spaced distally and become more spaced out proximally. Second antenna: The protopodite is relatively long (53 % CL). The slim first exopodite segment is quite short (19 – 20 % CL) and appears to lack a terminal seta. The remaining exopodite segments are just over 50 % the length of the first segment. The longest of the swimming setae is slightly longer than the protopodite. On the endopodite the g-seta is 45 % CL and the f-seta is 38 % CL; both are flattened and pointed. The c- and d-setae are slim and short, but the e-seta is moderately long. The h-seta is simple and subequal to the other sensory setae, i. e. 17 % CL. Both hook appendages are angled and terminally rounded; the distal arm of the smaller left hook is strongly curved. Mandible (Fig. 2 D): The first endopodite segment has a single subterminal dorsal seta with fine setules. It also has a ventral seta, which extends almost to the end of the limb. The longest claw seta on the end of the third segment is> 90 % the length of the limb and 22 – 23 % CL. The exopodite is a well developed process, which bears a slim, medium-length seta with long setules. The coxale is relatively short and about two-thirds as long as the endopodite. Maxilla: The endopodite has the usual setation for the tribe: four anterior setae, a single lateral seta, and three posterior setae. Terminally on its inner edge it has five small, sharp spines. The second segment has three terminal claw setae and two lateral slim setae. Fifth limb: The epipodial setae are in three groups of 4 setae. The basale has 3 + 1 ventral setae, 2 + 2 divergent lateral setae, and dorsally both a seta with long setules and a longer, bare, subterminal seta. On the first endopodite segment there is a pair of ventral medial setae, and a single medial dorsal seta. The terminal claw setae on the second segment have length ratios of 70: 100: 50 (dorsal to ventral). The longest of these three setae is 8 % CL and 65 % the length of the limb. Sixth limb: The epipodial setae are in three groups of 6 + 5 + 5. There are four ventral setae (1 + 1 + 2) on the basale, a single lateral seta, but no dorsal seta. The first endopodite segment has only a small medio-ventral seta. The second endopodite segment has a short dorsal and a short ventral seta; both are inserted at two-thirds of the length. The three subequal terminal setae are 47 % CL and about 130 % the length of the limb. All three have long setules distally. Caudal furca: The longest pair of the eight pairs of claw setae is nearly 17 % CL. Dorsally there is an unpaired seta, which is nearly quarter of the length of the longest claw setae. Copulatory appendage: The length of the appendage is 28 % CL. It is very broad, distally rounded, and terminally strongly tapered. There is a distodorsal stylet near its tip. It has 7 or 8 oblique muscle bands. Females. Carapace: In the Atlantic the length range is 0.76 – 0.86 mm; larger specimens of up to 1.20 mm reported from the Southern Ocean (Deevey 1982 a), may be a second species. The carapace is short, relatively high and slightly elongated. The maximum height of 52 – 60 % CL is located posterior to midlength, so the carapace tapers anteriorly. In ventral aspect the flanks curve smoothly. Uniquely the maximum width (42 – 47 % CL) is located at about two-thirds of the length of the carapace. Lrost is 8 to 9 % CL, but LC 3 is only about 4 % CL. The anterior margin of the carapace below the incisure barely arches anterior to the inner face of the incisure. The LAG opens about 11 % CL behind the tip of the rostrum, and 2 – 2.5 % CL behind the anterior end of the hinge. The RAG opens immediately below the posterior end of the hinge near the posterior dorsal corner. There is no surface sculpture. Frontal organ. The shaft and capitulum are fused, so the capitulum is poorly differentiated, although it is a little broader than the shaft, and is slightly down-turned. The capitulum is finely hirsute along its ventral margin, and its end is blunt or slightly pointed. The overall length of the frontal organ is 37 % CL and over double the length of the A 1 limb. First antenna. The length of the limb is 17 % CL, and the basal segments are fused. There is no dorsal seta. The e-seta is 35 % CL, similar in length to the frontal organ. Distal to the ends of the sensory setae, the trailing edge of the e-seta is lined with fine spines. The sensory a-, b-, c- and d-setae (19 % CL) are thin-walled and simple. Second antenna. The protopodite is 49 % CL. The first exopodite segment is slim and short (20 – 21 % CL). Unlike in the male, the female appears to lack a terminal seta on the first segment. The combined length of the remaining segments of the exopodite that carry the swimming setae is about half the length of the first segment. The longest swimming seta is a little shorter than the protopodite (44 – 45 % CL). The terminal setae on the endopodite are subequal in length (20 – 21 % CL), thin, and parallel-sided, with rounded tips. Mandible and Maxilla. Same as in the male. Fifth limb. The setal formula of the epipodial appendage is the same as in the male. The basale has five ventral setae (4 + 1), no (?) lateral seta, and the usual two dorsal setae, one with long setules and the other bare and longer. The first endopodite segment has a pair of medial ventral setae and a single medial dorsal seta. The length ratios of the terminal seta of the second segment are 78: 100: 76; the longest seta is 7.6 % CL and 65 % the length of the limb. Sixth limb. The epipodial appendage has three groups of setae, 6 + 5 + 5 as in the male. The basale has four ventral setae (2 + 2), a single lateral seta, and a short dorsal seta. The second segment has a single medial ventral seta, and the second segment single medial setae dorsally and ventrally. The length ratios of the terminal setae on the third segment are 65: 100: 44; the longest seta is 11 % CL and 85 % the length of the limb. Comparisons. Rotundoecia is most similar to Metaconchoecia. The characters that are most clearly discriminate these two genera are summarized in Table 9 and Appendices 1 – 3, and illustrated in Figure 2.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	discussion	Remarks. Iles (1953), when first describing Conchoecia teretivalvata, implied that it is conspecific with Müller’s (1894) Conchoecia rotundata short form from the Mediterranean and Müller’s coloured illustration (1894 plate 8 fig. 23) appears to support Iles’s conclusion. Gooday (1981) retained the name Conchoecia rotundata for another suitably sized and shaped Metaconchoecia species that occurs in the North Atlantic outside the Strait of Gibraltar. However, in his original description of Conchoecia rotundata from the Pacific Müller (1890) gives the length of the species to be 1.15 mm, so confirmation of the identity of both of the Mediterranean species (maybe both forms) and the Atlantic species is still needed. Sizes of specimens collected elsewhere in the tropical and temperate North Atlantic have all fallen within the size range given by Iles (1953) for R. teretivalvata. One of us (MVA) has re-examined material identified by Iles (1953) as Conchoecia teretivalvata and found in amongst typically sized specimens a few specimens that are> 1.0 mm in length. Similar larger sized specimens also occurred in material collected by RRS William Scoresby close to South Georgia (Station WS 143, at 53 ° 58 ’ S, 40 ° 30 ’ W); these large forms may well prove to be different Rotundoecia species. Deevey (1974: Fig. 4 a, c – e, j, l) illustrated a “ larger form ” of Conchoecia teretivalvata from the South Atlantic, and showed both sexes as having carapaces that are less globose than the typical form (CH 50 % CL compared with the typical CH of 55 – 60 % CL). Thus we expect that the number of species attributed to this genus will increase as more material, particularly from high southern latitudes is examined. Believing Iles (1953) had failed to designate either type specimens or a type locality for Conchoecia teretivalvata in his original description, so we selected a male and a female from Iles’s original Benguela Current samples to serve as comparative material for the species. Both specimens are from RSS William Scoresby station WS 977, (6 March 1950) 22 ° 39 ’ S, 12 ° 16 ’ E, and were collected from a depth of 250 – 100 m. These have been deposited together in the British Museum (Natural History) (♂ 2004.2552, ♀ 2004.2553). However, when going through an accumulation of material rescued from Iles’s garage two years after his death, slides of dissected male and female specimens were found which had been clearly marked as types. These slides have been deposited in the British Museum (Natural History) — holotype a male 2009.262, paratypes two females 2009.263 and 264. Entirely fortuitously the type material came from exactly the same sample from which the comparative material had been selected earlier.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
03DC87FDEC22FFE26FDCFBB8A2B6FE22.taxon	distribution	Distribution. Atlantic Ocean and Mediterranean Sea: occurs in the latitude range from 60 ºN to 49 ºS (Müller 1894; Iles 1953; Angel 1968 a, 1977, 1979, 1981 b, 1983 b, 1984; Angel & Fasham 1975; Deevey 1974; 1978 b, Gooday 1981; Ellis 1985). Indian Ocean: known only from 4 ºN, 78 ºE (Gooday 1981). Pacific Ocean: found from 22 ºS to 27 ° S (Poulsen 1973; Martens 1979). Deevey (1978 a, 1982 a, 1983) extended its range in the Pacific sector of the Southern Ocean to 65 ° S. In the literature the bathymetric range is given as 0 – 2000 m, but stratified sampling in the Northeast Atlantic shows that its bathymetric range is 25 – 500 m.	en	Chavtur, Vladimir G., Angel, Martin V. (2011): Revision of Metaconchoecia (Ostracoda: Halocyprididae) and the designation of two new tribes Conchoeciini and Metaconchoeciini 2857. Zootaxa 2857 (1): 1-87, DOI: 10.11646/zootaxa.2857.1.1, URL: https://biotaxa.org/Zootaxa/article/view/zootaxa.2857.1.1
