taxonID	type	description	language	source
3F1387DAFFE21F6BBF75FD0DFBDF968D.taxon	description	De W nition Carapace reduced, leaving last ® ve thoracic somites uncovered. Telson entire, sub-triangular, armed with pair of distal spines, no plumose setae on all margins. Exopod of uropod shorter than endopod, armed laterally with a few setae on posterior half. Eye well developed, cornea globular. Antennule with peduncular segment 3 robust and longest, bearing three to ® ve sensory setae at base of outer ¯ agellum, inner ¯ agellum very short, composed of four or ® ve articles, male lobe undeveloped. Antennal scale vestigial. Labrum evenly convex anteriorly, without frontal process or spine. Endopods of thoracic limbs 3 ± 8 rather stout, carpo-propod i unsegmented, shorter than meri. Male pleopods rudimentary, unsegmented, pleopod 1 with procurved long seta distally, pleopod 4 ending in strong spine. Female pleopods tiny, unsegmented. Marsupium consisting of two pairs of lamellae. Type species. Palaumysis simonae Bacescu and IliOEe, 1986. Remarks Bacescu and IliOEe (1986 b) reported that Palaumysis simonae has no antennal scale. However, re-examination of the paratypes (USNM 227132) and further specimens from the Palau Islands showed that P. simonae possesses a sharp, small process arising from the distodorsal part of the protopod of the antenna. Detailed SEM observations veri ® ed this process to be a reduced scale. The original authors might have overlooked this structure. Bacescu and IliOEe (1986 b) proposed the tribe Mancomysini to receive Palaumysis simonae. Nouvel et al. (1999), in contrast, assigned this genus to the tribe Erythropini, and Michthyops W. M. Tattersal l to a new taxon Calyptommini, without a detailed justi ® cation for this classi ® cation. Although Palaumysis resembles certain Erythropini genera in the shape of the telson, possessing a rudimentary antennal scale and rather stout thoracic endopods, this genus is remarkable in having a combination of the following features: the carapace is considerably reduced, the pleopods are tiny in both sexes and the inner ¯ agellum of the antennule is much reduced. We are inclined to support Bacescu and IliOEe’s scheme, giving more weight to reduced, unsegmented male pleopods. Recently, OrtõÂz et al. (1997) reported an interesting mysid, Gironomysis lalanai, from an anchialine cave in Cuba. Gironomysis in general resembles Palaumysis in having a reduced antennal scale, tail fan and other appendages. However, the carapace of Gironomysis covers nearly the whole of the thoracomeres and the inner antennular ¯ agellum has an extraordinary elongated terminal article, which is unusual in all other known mysids. Males of Gironomysis have not been discovered yet, so debate on the higher taxonomic position of this mysid deserves future studies.	en	Hanamura, Yukio, Kase, Tomoki (2002): Marine cave mysids of the genus Palaumysis (Crustacea: Mysidacea), with a description of a new species from the Philippines. Journal of Natural History 36 (3): 253-263, DOI: 10.1080/00222930010004241, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930010004241
3F1387DAFFE51F69BF3AFD60FCBD92D0.taxon	description	Palaumysis simonae Bacescu and IliOEe, 1986 b: 31, ® gure 2. Material examined PARATYPES (USNM 227132): 12 males (1.2 ± 1.4 mm), ® ve females (1.5 ± 1.6 mm), one juvenile (1.0 mm), cave, 10 m, Caroline Island, Palau Islands. Others. Seven males (ca 1.0 ± 1.4 mm), four females (1.3 - 1.5 mm), St. VH,`Virgin Hole’, W Ngemelis Island, Palau Islands, 07 ss 07 ¾ 18.5 ² N 134 ss 14 ¾ 14.7 ² E, 17 m, submarine cave, totally dark inside, calcareous muddy sand, 23 December 1999, leg. Ohashi, Kinjo, Hayami and Kase (NSMT Cr 13082). One male (1.4 mm), St. NK,`Nikko Cave’, Palau Islands, 07 ss 08 ¾ 49.0 ² N 134 ss 09 ¾ 56.4 ² N, 12 ± 15 m, submarine cave seemingly connected with an anchialine pond, totally dark inside, mud, 26 December 1999, leg. Ohashi, Kinjo, Kase, Tabuki and Kano (NSMT Cr 13083). Description. Carapace reduced, fused with anterior three thoracic somites, without unfused free lobule posteroventrally, consequently leaving uncovered last ® ve thoracic somites as well as ventrolateral parts of anterior three thoracic somites; anterior margin produced into sub-triangular rostral plate with obtuse apex; anterolateral part forming acute angle; cervical groove distinct (® gure 1 a, d, e). Telson sub-triangular, with pair of distal spines, without plumose setae on all margins. Uropod narrow, exopod shorter than endopod, armed with three lateral setae and numerous long setae on distal and distomesial margins; endopod with long setae distally; statocyst present on proximal part of endopod. Antennule with last segment of peduncle robust and longest, armed with three to ® ve, usually four, sensory setae at base of outer ¯ agellum, male lobe undeveloped, inner ¯ agellum composed of four articles (® gure 2 a, c). Antennal scale rudimentary, with minute terminal seta, latter hardly seen under light microscope (® gures 1 b, 2 a, b). Labrum somewhat produced anteriorly, without frontal spine or process (® gure 1 c). Endopods of thoracic limbs 3 ± 8 rather stout, carpo-propodi unsegmented. Male pleopods rudimentary, unsegmented; pleopod 1 with long, plumose terminal seta, curving anteriorly, and few short setae distally (® gure 1 f); pleopod 4 armed with a few lateral setae, ending with stout terminal spine, distal end slightly exceeding beyond posterior margin of abdominal somite 5; pleopods 2, 3 and 5 similar in shape (® gures 1 g, 2 d). Female pleopods tiny, unsegmented; pleopod 1 with procurved long, plumose terminal seta in immature females, but normally absent in mature females; pleopods 2 ± 5 similar in shape, armed with about three setae. Lamellar epipod on thoracic limb 1. Female marsupium consisting of two pairs of lamellae. Colour The entire body is assumed to be semi-transparent as the foregut can be seen through the exoskeleton, and the uropod and distal parts of thoracic limbs with light brownish setae (based on specimens about one month after preservation in 10 % seawater formalin). Body size Total length does not exceed 2 mm, and females become larger than males. Remarks Bacescu and IliOEe (1986 b) did not give detailed accounts for the general form of the carapace of Palaumysis simonae. It is very remarkable for its reduced size, covering only the dorsal and dorsolateral parts of the anterior three thoracic somites, and is completely fused with the anterior thoracomeres, in consequence with no unfused free lobe posteroventrally. The original authors mentioned that the pleopods of Palaumysis simonae do not diOEer between the sexes, in that females have a long terminal spine as males do (Bacescu and IliOEe, 1986 b; ® gure 2 f). Although one paratype female was recognized as possessing such an end-piece, the remaining females did not bear it. This suggests that the presence of the terminal spine in females represents an aberrant condition. The ® rst pleopod, otherwise, has a procurved long seta in males and immature females, but it is not present in mature females. For distinction from the Philippines population, see the`Remarks’ section under the following species. Distribution Palau Islands; 10 ± 24 m (Bacescu and IliOEe, 1986 b; present study).	en	Hanamura, Yukio, Kase, Tomoki (2002): Marine cave mysids of the genus Palaumysis (Crustacea: Mysidacea), with a description of a new species from the Philippines. Journal of Natural History 36 (3): 253-263, DOI: 10.1080/00222930010004241, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930010004241
3F1387DAFFE71F64BF78FA01FCF4968D.taxon	materials_examined	Material examined HOLOTYPE (NSMT Cr 13080): adult male (1.8 mm),`Mapating Cave’ diving site, St. AN- 3, SW Maricaban Island, Batangas, Philippines, 13 ss 40 ¾ 09.0 ² N, 120 ss 48 ¾ 58.2 ² E, 46 m, submarine cave, total darkness inside, calcareous sand, 20 November 1998, leg. Ohashi, Kinjo, Tabuki, Cabrera and Kase. PARATYPES (NSMT Cr 13081): 52 males (1.6 ± 1.9 mm), 29 females (1.8 ± 2.3 mm) including at least four ovigerous females (2.0 ± 2.3 mm), three juveniles (1.1 ± 1.3 mm), one ind. (damaged), data same as for the holotype. Description Small-sized mysid, with external surface smooth and no folds or spines (® gure 3 a, b). Carapace reduced, fused with anterior three thoracic somites, with small unfused lobe posteroventrally; posterior margin nearly straight, leaving last ® ve thoracic somites uncovered; anterior margin produced into triangular rostral plate with somewhat rounded apex; anteroventral corner forming acute angle; cervical groove marked (® gure 3 a ± c). Abdomen with ® rst ® ve somites subequal in length, somite 6 about twice length of somite 5 and stouter than anterior somites (® gure 3 a, b). Telson entire, subtriangular, nearly as long as maximum width, armed with pair of distal spines, no plumose setae on all margins (® gure 3 d). Exopod of uropod narrow, somewhat truncate distally, extending distinctly beyond end of telson, armed laterally with three short setae on distal half, increasing in length distally, distal and mesial margins armed with numerous long setae (® gure 3 d). Endopod of uropod narrow, longer than exopod, armed with numerous long setae on lateral and mesial margins; statocyst present (® gure 3 d). Eye developed, cornea well pigmented, globular, distinctly larger than eye stalk (® gure 3 b, c). Antennule with peduncular segment 3 robust and longest, with single seta on distomesial margin and about four sensory setae at base of outer ¯ agellum, male lobe undeveloped, inner ¯ agellum very short, consisting of ® ve segments, armed with terminal seta; peduncular segment 2 shortest; peduncular segment 1 slightly longer than 2 (® gure 3 e). Antenna with rudimentary scale, sub-lanceolate, slightly curving inwards, with somewhat obtuse distal margin, armed with long terminal seta and few short setae on lateral margin (® gure 3 f). Labrum with anterior margin somewhat evenly convex, without frontal process or spine (® gure 3 g). Mouthpart s as illustrated (® gure 4 a ± e). Thoracic limbs 3 ± 8 rather stout, all similar in shape; exopods with distal segment composed of six or seven subsegments; endopods with carpo-propodi unsegmented, shorter than merus, dactylus short, with stout terminal seta (® gure 4 f). Lamellar epipod on thoracic limb 1 (® gure 1 a). Penis rod-shaped, with single seta distally. Marsupium consisting of two pairs of lamellae, anterior one smaller than posterior. Pleopods in males rudimentary, unsegmented (® gure 4 g ± k); pleopod 1 with long, anteriorly curving plumose seta and a few short setae distally; pleopods 2, 3 and 5 similar in shape, posteriormost slightly longer than others, armed with about three setae distally; pleopod 4 laterally armed with two or three setae, distally ending in strong spine, reaching anterior one-third to one-half of abdominal somite 6, articulation between pleopodal plate and terminal spine indistinct. Pleopods in females tiny, armed with three to ® ve setae distally; pleopod 1 in immature females, like males, with long, anteriorly curving plumose terminal seta, but no plumose seta in mature females; pleopods 2 ± 5 similar in shape (® gure 4 l, m). Colour The entire body in live specimens is assumed to be semi-transparent, since the foregut can be seen through exoskeleton in preserved specimens (about 6 months after preservation in formalin seawater). Body size Largest male is 1.9 mm in total length, largest female is 2.3 mm. Females at a size of 2.0 mm or greater could carry embryos. Embryo Larval development of Palaumysis philippinensis is illustrated in ® gure 5. The Stage I embryo (egg) is horse bean-shaped, 0.38 mm along the longest axis (® gure 5 a), and 1.00 mm in Stage III larvae (® gure 5 f). Although the general form of embryos is not so diOEerent from other members of the Mysidae, the Stage II larvae (® gure 5 c ± e) were noted to have proportionately long antennule and antenna: e. g. Archaeomysis in Hanamura (unpublished); Gastrosaccus in Brown and Talbot (1972); Leptomysis in Wittmann (1981); Misidium in Davis (1966); and Neomysis in Murano (1964). The observed maximum clutch size of Palaumysis philippinensis was two. Presumably, P. philippinensis does not carry more than two eggs as the size of female marsupium is not enough to cover all the embryos even in early stage eggs, and in Stage III larvae only a posterior part of the abdomen is covered by both sides of the marsupial lamellae. Larvae of Palaumysis philippinensis might be released from the marsupium at a size of 1.0 ± 1.1 mm, since the smallest free-living juvenile was 1.1 mm. Etymology The speci ® c name is derived from the type locality; it is used as an adjective, in agreement with the gender (feminine) of the generic name. Remarks Palaumysis philippinensis is distinguished immediately from P. simonae by the carapace with a small unfused lobe posteroventrally, as opposed to having no such free lobe. Palaumysis philippinensis also diOEers from P. simonae in the following minor particulars: the antennal scale in the new species possesses a long terminal seta in contrast to bearing a minute seta; the inner ¯ agellum of the antennule is consistently composed of ® ve articles as against four, and the male fourth pleopod is proportionately longer, reaching to anterior one-third to one-half of the sixth abdominal somite, while it slightly extends beyond the posterior end of the ® fth abdominal somite in P. simonae. In general appearance, P. philippinensis appears to have relatively more primitive features than P. simonae. Distribution Known only from the type locality in the Philippines; 46 m.	en	Hanamura, Yukio, Kase, Tomoki (2002): Marine cave mysids of the genus Palaumysis (Crustacea: Mysidacea), with a description of a new species from the Philippines. Journal of Natural History 36 (3): 253-263, DOI: 10.1080/00222930010004241, URL: http://www.tandfonline.com/doi/abs/10.1080/00222930010004241
