taxonID	type	description	language	source
03C887E5FFEEFF97FF12A7C1FEBAFCDC.taxon	materials_examined	Type species. Acanthohalacarus reticulatus Bartsch, 2001. Adults. Genital and anal plates fused. Female GA with five (rarely four or six) pairs of slender pgs, genital sclerites with two pairs of short sgs. Genital acetabula internal; posterior-most pair of acetabula larger and removed from two anterior pairs (Fig. 1). Ovipositor at rest extending beyond anterior margin of GO. With short basal pair and slender, spiniform apical pairs of genital spines; number of spines not known. Male GO in ventral position, smaller than that of female (Bartsch 2001 a: fig. 1 D), in single species known surrounded by 45 – 57 slender and smooth pgs; several of pgs outlying. Genital sclerites with five pairs of short sgs, two anterior pairs setiform, three posterior ones short, spiniform. Acetabula adjacent in posterior half of GO, the three pairs short, equal-sized, cupuliform (Fig. 2). Anterior epimeral plate without epimeral pores. Juveniles. One larval and two nymphal stages known. Nymphs with genital plate separated from anal plate. Deutonymphal GP with two pairs of pgs, at least one pair of minute sgs and two pairs of internal gac (Bartsch 2001 a: fig. 3 B). Protonymphal GP with single pair of gac; pgs and sgs lacking. Nymphs without but larva with pair of epimeral pores (Bartsch 2001 a: fig. 3 F).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEEFF97FF12A7C1FEBAFCDC.taxon	discussion	Remarks. At present a single species is known, collected on a seamount in the northeastern Atlantic Ocean (Bartsch 2001 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEEFF97FF12A4B2FEB8F983.taxon	materials_examined	Type species. Acarochelopodia delamarei Angelier, 1954. Adults. Female GA with three pairs of slender pgs; sgs lacking (Bartsch 1984 b: fig. 19). Ovipositor short, at rest not extending beyond GO. Genital spines not strongly sclerotized, their number and shape not known. Male GO situated as in female, but, in relation to size of GA, GO smaller than in female. Male GA with about seven pairs of setiform pgs, genital sclerites with three pairs of short sgs and three pairs of small gac (Fig. 3; Bartsch 1977 b: fig. 312). AE of female and male without epimeral pores. Juveniles. A larval and two nymphal stages known. In nymphal instars GP and AP separated. Deutonymphal GP with two pairs of gac and two pairs of pgs, but no sgs (Fig. 4; Bartsch 1977 b: fig. 313). Protonymphal GP with single pair of internal gac; pgs and sgs not developed. In deuto- and protonymphs epimeral pores absent. Larva with longitudinally divided (as in adults and nymphs) or undivided AE; each half with a pair of delicate, tube-like epimeral pores (omitted in Bartsch 1977 b: fig. 317).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEEFF97FF12A4B2FEB8F983.taxon	discussion	Remarks. The ten species described are recorded from temperate and tropical regions of the Atlantic, Indian and Pacific Ocean and from tidal and shallow water areas (Bartsch 2009 a; Pepato et al. 2011). All species are psammophilous.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEEFF94FF12A147FAF7FEE2.taxon	materials_examined	Type species. Acaromantis squilla Trouessart & Neumann, 1893. Adults. GP and AP in female and male fused. Female GA with four pairs of pgs; sgs lacking. GO small, in posterior half of genital plate (Bartsch 1977 b: fig. 418). Ovipositor short, at rest not extending beyond GO. Genital acetabula small, three pairs arranged along periphery of internal sacculus (Fig. 5). Genital spines not sclerotized, apical ones flattened, number not known. Male GA with 15 – 20 pgs arranged in a ring around GO and zero to three pairs of outlying setae; pgs smooth or slightly plumose (Bartsch 1977 b: fig. 413). Each genital sclerite with three minute sgs. GO smaller than in female though in similar position. Female and male with pair of epimeral vesicles, each vesicle including an epimeral pore. Juveniles. With a larval and two nymphal stages. In proto- and deutonymph GP separated from AP. Deutonymphal GP with two pairs of internal gac, one pair of pgs but no sgs (Bartsch 1977 b: fig. 416). Protonymphal GP with pair of minute pores which may be remnants of genital acetabula (Fig. 6); no setae present. Nymphs and larva with large epimeral vesicles, each one with internal epimeral pore.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEEFF94FF12A147FAF7FEE2.taxon	discussion	Remarks. Eleven species of this genus are presently described. The records are from tropical and temperate zones of the Atlantic and Pacific Ocean, mostly from tidal and subtidal sandy deposits (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF94FF12A6A7FC41FC41.taxon	materials_examined	Type species. Acarothrix palustris Bartsch, 1990. Adults. GP and AP in female and male fused; GO in about middle of GA. Female GA with three pairs of pgs; genital sclerites with pair of sgs; single pair of gac in internal position just posterior to middle of GO (Bartsch 2006 a: figs 2, 18). Ovipositor at rest slightly extending beyond GO. Most of apical genital spines short, distinctly sclerotized, partly bifid. In ventral aspect, when ovipositor at rest, two pairs of anterior apical genital spines seen. There may be another seven spines, but as obscured, exact number not known. Male GO slightly smaller than that of female. Male GA with about 9 – 14 pairs of slender pgs; genital sclerites with four pairs of sgs, two setiform anterior pairs and a spiniform and setiform posterior pair. Pair of acetabula external, situated in posterior part of genital sclerites (Bartsch 1990 a: figs 4, 5, 2004 c: fig. 2 D, 2006 a: fig 12). AE with pair of epimeral pores. Juveniles. With a larval and a single nymphal stage. In protonymph GP separated from AP. GP with single pair of small internal gac; pgs and sgs lacking. Shape of larval epimeral pores same as in adults and protonymph.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF94FF12A6A7FC41FC41.taxon	discussion	Remarks. The five species to date known are spread world-wide, all records are from warm-temperate and tropical brackish waters (Bartsch 2009 a; Chatterjee et al. 2012, 2013).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF94FF12A304FBE4F8A0.taxon	materials_examined	Type species. Actacarus pygmaeus Schulz, 1937. Adults. GP and AP fused. Female GA with two to three (to five) pairs of smooth pgs. Subgenital setae lacking. GO in posterior part of GA. Ovipositor at rest extending beyond GO, in some species even beyond anterior margin of GA. Everted ovipositor apically with pair of slender, seta-like anterior and seven posterior genital spines. These spines setiform (Konnerth-Ionescu 1970: pl. 1 E) or dissimilar in shape, hooked and spiniform (Bartsch 1999 a: figs 18, 19; Schulz 1937: fig. 1 C). Spines weakly sclerotized. Acetabula small, from almost equal- to unequal-sized, three pairs about level with mid-GO (Fig. 7; Abé 1990 a: fig. 2 F, 1997: fig. 4 E; Newell 1984: fig. 703). GO in male slightly smaller than in female and removed from posterior margin of GA. GA with 7 – 18 pairs of slender, smooth pgs situated either close around GO or lateral and posterior to GO; one pair of setae outlying. Each genital sclerite with one to three sgs. GO with three pairs of small acetabula (Abé 1997: fig. 4 F). AE in both male and female without epimeral pores. Juveniles. A larval and two nymphal stages known. Deutonymph with GP and AP partly or completely separated (Bartsch 1977 b: fig. 104; Abé 1997: fig. 4 G) or fused (Bartsch 1977 b: fig. 104, 1999 a: fig. 23; Abé 1990 a: fig. 4 B). Deutonymphal GP with two pairs of internal gac and two pairs of pgs; sgs lacking. In protonymph GP and AP fused (Abé 1990 a: fig. 5 B; Bartsch 1999 a: fig. 25). Protonymphal GA with single pair of internal gac; pgs and sgs not developed. Larva with large anal plate. Epimeral pores vestigial or lacking (Bartsch 1977 b: fig. 106, 1999 a: fig. 27; Abé 1990 a: fig. 6 B).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF94FF12A304FBE4F8A0.taxon	discussion	Remarks. Actacarus species are inhabitants of sandy deposits; 24 species are known to date (Bartsch 2009 a). The genus is spread world-wide in tropical, warm- and cold-temperate regions.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF95FF12A071FA7DFDE6.taxon	materials_examined	Type species. Halacarus parvus Chilton, 1883. Adults. In female and male GP and AP fused. Female and male GO in ventral position, often almost similarsized and removed from anal cone by almost the same distance. Female GA with three to about 20 pairs of pgs, genital sclerites with zero to two pairs of sgs. Ovipositor at rest generally extending beyond anterior margin of GO and often reaching to or beyond anterior margin of GA. Number and shape of genital spines not described. Females with three pairs of rather large internal acetabula, these either equal-sized (Bartsch 1999 c: fig. 5 C) or posteriormost one larger than anterior pairs of acetabula (Chang & Chatterjee 2006: fig. 1 B, C). Male with more than 80 pgs densely arranged around GO, pgs often filiform, rarely delicately plumose. Genital sclerites with five pairs of spurlike sgs. With three pairs of large gac, posterior-most pair may be somewhat enlarged (Bartsch 1999 c: fig. 4 C). Neither female nor male AE with epimeral pores. Juveniles. With larval and two nymphal stages. Genital plate of nymphs often small, separated from anal plate. Deutonymph with two pairs of internal gac, single pair of pgs and either zero or two pairs of sgs (Fig. 8; Chang & Chatterjee 2006: fig. 4 B). Protonymph with pair of internal gac; pgs and sgs lacking. Larva with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFEDFF95FF12A071FA7DFDE6.taxon	discussion	Remarks. More than 40 valid species are at present known. The genus is spread world-wide (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFECFF95FF12A5ABFD4FFC6D.taxon	materials_examined	Type species. Agauides cryosi Bartsch, 1988.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFECFF95FF12A5ABFD4FFC6D.taxon	description	Female. Genitoanal plate with four to seven pgs on either side of GO (Bartsch 1988 a: fig. 53, 1989 b: fig. 11). GO in ventral position. Genital sclerites lack sgs. Number and shape of genital acetabula and spines not mentioned in the descriptions. Epimeral pores lacking. Male, nymphs, larva. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFECFF95FF12A5ABFD4FFC6D.taxon	discussion	Remarks. Two species are at present described from the northeastern and southern Pacific Ocean, collected in 600 and 1500 m depth (Bartsch 1988 a, 1989 b).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFECFF95FF12A32BFEBBF875.taxon	materials_examined	Type species. Agaue brevipalpus Trouessart, 1889. Adults. In both female and male GP and AP fused. Female GP with (two to) three (to four) pairs of pgs, these setae filiform and smooth, rarely with delicate filaments (e. g. Otto 1999 a: fig. 7 C). GO in posterior half of GA. Each genital sclerite with zero to four sgs. Three pairs of gac either almost equal-sized and adjacent (Fig. 9; Benard 1962: fig VIII, 3) or somewhat different in length and separated into two adjacent anterior and a third posterior pair (Figs 13, 14; Bartsch 1977 b: fig. 276). Ovipositor at rest short, if at all only slightly extending beyond GO. Genital spines generally distinctly sclerotized (brown colour), palmate and flattened, ending with several small tines (Otto 1994: fig. 11) or spiniform, smooth and slender. Basal pair of spines in some species absent in other species present (Figs 9, 13, 14). Ovipositor apically with two pairs of anterior and three or four pairs of posterior genital spines (Fig. 11; Benard 1962: fig VIII, 3). Male GA often somewhat smaller than that of female. Plate with 15 – 50 pairs of setiform pgs, these generally smooth, rarely plumose (Newell 1984: fig. 631; Bartsch 1985 c: fig. 8, 2007 b: fig. 4 C; Otto 1999 a: figs 8, 11), arranged close around GO; often one pair of setae outlying. Distance between GO and anal cone almost the same or slightly larger than in female. Genital sclerites with three to five pairs of short, often spurlike sgs. GO with two or three pairs of gac (Figs 10, 12, 15); third pair may be obscured by internal sclerites. Most species with small epimeral pores, with slit-like opening; in a few species epimeral pores obscured by apodemes or lacking. Juveniles. With a larva and two nymphal stages. In most nymphal stages GP and AP separated (e. g. Krantz 1973: figs 13, 14; Bartsch 1996 c: figs 31, 34), in a few species GP and AP fused (Bartsch 1984 b: fig. 10). Deutonymphal GP with two pairs of internal gac, two pairs of pgs and zero to two pairs of sgs (Krantz 1976: fig. 29; Bartsch 1984 b: fig 10, 1996 e: p. 705, fig. 29; Pepato & Tiago 2005: fig 4 E). Protonymphal GP with single pair of gac; neither pgs nor sgs present. Larval AE always with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFECFF95FF12A32BFEBBF875.taxon	discussion	Remarks. Agauopsis includes more than 80 species (Bartsch 2009 a). The majority of species can be attributed to species groups (cf. Bartsch 1986 c, 2005 d), most of these groups are spread all around the globe. The genus is in need of revision.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF9BFF12A787FDECFCB1.taxon	materials_examined	Type species. Halacarus anomalus Trouessart, 1894. Adults. Female GP divided; a pair of elongate or triangular plates flanking GO. Plate often with genital groove posterior to GO. Female GO elongate, with single pair of internal gac (Bartsch 1976 a: figs 22, 38, 1979 b: fig. 59). Anterior pair of three pairs of pgs in striated integument or on minute median platelet, two pairs of pgs on pair of genital plates. Subgenital setae lacking. Ovipositor at rest from hardly to distinctly extending beyond GO. On everted ovipositor one pair of short basal and five pairs of elongate apical genital spines seen; the latter in a combination two anterior and three posterior pairs. Two anterior pairs of genital spines with truncate tip (Bartsch 1976 a: fig. 40). Male GP and AP contiguous, with 7 – 50 pairs of filiform pgs flanking genital opening and genital groove. GO shorter than in female and in more ventral position. Each genital sclerite with three (rarely two) short sgs. With single pair of small internal gac in posterior part of GO (Bartsch 1976 a: fig. 6, 1979 b: fig. 58). In most females and males AE longitudinally divided into right and left half, each half with an epimeral pore. Juveniles. With a larval and a single nymphal stage. In protonymph genital and anal plate contiguous; GP with pair of small internal gac and pair of pgs but no sgs (Bartsch 1976 a: figs 13, 31, 1979 b: fig. 64). Genital area often with genital groove. Protonymph and larva with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF9BFF12A787FDECFCB1.taxon	discussion	Remarks. Nineteen species are described (Bartsch 2009 a), all are psammobionts. The majority of species is recorded from the northern Atlantic Ocean; species from the Indian and Pacific Ocean differ in several characters from the boreal Atlantic species.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF9BFF12A495FB5AFA38.taxon	materials_examined	Type species. Arenihalacarus imamurai Abé, 1991. Adults. Female GP divided into four plates (Abé 1991: fig. 1 B, D); genital area with two pairs of slender pgs and at least one pair of robust internal gac. GO situated terminally, close to anal plate. No sgs on genital sclerites. Ovipositor at rest extending beyond anterior genital plate. Genital spines slender; number not known. Male GP uniform; 12 pairs of slender, filiform pgs situated lateral and posterior to GO. GO with single pair of distinct internal acetabula. Genital sclerites with three pairs of short, spiniform sgs (Abé 1991: fig. 1 F). Female and male AE longitudinally divided, either half with epimeral pore. Juveniles. With larva and at least two nymphal stages, the deutonymph and protonymph. Genital plate of deutonymph with two pairs of pgs and two pairs of gac; sgs lacking (Abé 1991: fig. 2 E). Genital plate of protonymph with single pair of pgs and pair of internal gac; sgs lacking (Abé 1991: fig. 2 F). Larval AE longitudinally divided and with epimeral pores (Abé 1991: fig. 2 G).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF9BFF12A495FB5AFA38.taxon	discussion	Remarks. The single species presently known was extracted from sublittoral sandy deposits from the nortwestern Pacific Ocean (Japan) (Abé 1991). The larval genital plate (Abé 1991: fig. 2 H) may be an anomaly or an enlarged anal plate.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF99FF12A10EFDBDFDBB.taxon	materials_examined	Type species. Copidognathus (Arhodeoporus) arenarius Newell, 1947. Adults (differing characters of species of the A. bonairensis and A. bucculentus groups are in square brackets). In female and male GP and AP fused. Female GA with three pairs of pgs; genital sclerites with (zero to) one to two (to three) pairs of sgs. GO with two pairs [a single pair] of small, tube-like gac (Figs 16, 19, 21; Bartsch 2003 d: fig. 5 E; Newell 1971: fig. 59). If two pairs present, these situated immediately adjacent, either anterior to and somewhat posterior to middle of GO. Ovipositor at rest extending anteriad from slightly to far beyond GO. On everted ovipositor one or two pairs of anterior and seven posterior genital spines visible (Fig. 17; Bartsch 1977 a: figs 5, 14, 1991 b: fig. 4). Genital spines short, weakly sclerotized, flattened or rather long and slender. GO in male almost as long as in female but distance to anal cone longer than that in female. GA with [one to] two pairs of internal acetabula (Figs 18, 20; Bartsch 1997 b: fig. 37, 2003 d: fig. 5 C), 7 – 20 pairs of smooth and slender pgs and four to five (rarely three or six) pairs of sgs, most of setae filiform though one to three may be spur-like. Adults with pair of epimeral pores. Juveniles. One larval and two (?) nymphal stages known. Deuto- and protonymphal GP separated from AP. Deutonymphal GP with two pairs of pgs, zero to one pair of sgs and two pairs [single pair] of small internal gac (Fig. 22; Bartsch 1977 a: fig. 9, 1977 b: fig. 239, 1991 c: fig. 4 K); in small-sized A. nanus Bartsch, 2009 gac vestigial (Bartsch 2009 c). Protonymph with single pair of gac near posterior margin of GP; pgs and sgs lacking. Larva with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE2FF99FF12A10EFDBDFDBB.taxon	discussion	Remarks. The genus Arhodeoporus is spread world-wide and more than 30 species are described. On the basis of external characters, several distinctly separate species groups have been characterized (Bartsch 1983 b, 1997 b). The genus is in need of revision. Adults of A. bonairensis (Viets, 1936) and A. wadjemupis Bartsch 1997 have a single pair of genital acetabula. The two species belong to the A. bonairensis and A. bucculentus groups, respectively. No protonymphs have been recorded of species of these groups. The genus Plegadognathus Morselli, 1981 may have to be re-established to include the species of these two groups.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF99FF12A58FFACCFB89.taxon	materials_examined	Type species. Astacopsiphagus parasiticus Viets, 1931. Adults. No description given. Juveniles. A single nymphal stage known, supposedly a tritonymph. GP and AP not fused. About 18 setae (perigenital setae) in anterior part of tritonymph, two pairs of setae (subgenital setae?) just anterior to primordial genital slit and about 70 external acetabula (34 – 38 pairs) in posterior part of GP (Viets 1931: fig. 4). Epimeral pores not mentioned.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF99FF12A58FFACCFB89.taxon	discussion	Remarks. Juveniles of this species have been found in eastern Australia (Queensland) on a freshwater decapod (Crustacea), the mites' mouthparts fixed to the gills (Viets 1931). The species is in need of a careful re-description on the basis of new material. The genus Astacopsiphagus is omitted in the course of further evaluations.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF99FF12A37CFD9BF958.taxon	materials_examined	Type species. Atelopsalis tricuspis Trouessart, 1896. Adults. Both female and male with GP and AP fused; GO in both sexes almost equal in size and position. Female GA with three pairs of slender pgs, genital sclerites with one to two pairs of sgs. With two pairs of gac, these at least in some species enlarged, tube-like and situated either in anterior (Pepato & Tiago 2004: fig. 1 B) or posterior half of GO (Fig. 23). Ovipositor short, at rest not or hardly extending beyond GO. Genital spines delicate, spiniform, number not known. Male GA with four to five pairs of slender pgs, two or more arising from alveoli, and four pairs of minute sgs. Two pairs of partly fused acetabula in posterior part of GO (Bartsch 2002: fig. 16). AE of females and males with pair of epimeral vesicles, each with inner transparent ovate area (Bartsch 2002: fig. 18). These areas assumedly equivalents to epimeral pores. Juveniles. In deuto- and protonymph GP separated from AP. GP of deutonymph with primordial genital foramen, rather than genital slit, including two pairs of acetabula; GP with two pairs of pgs; sgs lacking (Bartsch 1985 c: fig. 20). Protonymphal GP similarly with primordial genital foramen (Pepato & Tiago 2004: fig. 2 B), this with pair of gac (Fig. 24); pgs and sgs lacking. Larva, as adults and nymphs, with pair of large epimeral vesicles.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF99FF12A37CFD9BF958.taxon	discussion	Remarks. The eight species at present known are spread in warm-temperate and tropical zones of the Atlantic, Indian and Pacific Ocean (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF9EFF12A039FECBFDE6.taxon	materials_examined	Type species. Australacarus inexpectatus Bartsch, 1987. Adults. Female and male with GP and AP fused (Bartsch 1987 a: figs 9, 10). Female GA with two to three pairs of slender pgs; genital sclerites without sgs. Three pairs of internal acetabula equal-distanced, arranged in line and extending beyond middle of GO (Fig. 25). Ovipositor short, number and shape of genital spines not known. Male GA with genital groove posterior to GO. In contrast to females, GO of males removed from basis of anal sclerites. With 7 – 25 pairs of slender pgs arranged lateral to GO and genital groove (Bartsch 1987 a: fig. 10, 1993 a: fig. 8; Otto 2000 c: fig. 6 F). Male genital sclerites with four pairs of sgs. Three pairs of gac small, internal, situated adjacent in posterior half of GO (Fig. 26). Epimeral pores in general inconspicuous, but illustrated in one species (A. zagorskisae Otto, 2000) (Otto 2000 c: fig. 6 E). Juveniles. One larval and one nymphal stage described. Nymphal stage, the deutonymph, with genital plate separated from anal plate. GP with two pairs of internal gac, single pair of pgs; sgs lacking (Bartsch 1993 a: fig. 7; Otto 2000 c: fig. 2 H). Larval stage without genital plate. No notes given on epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE0FF9EFF12A039FECBFDE6.taxon	discussion	Remarks. The records of the five species at present known are from the southern hemisphere (Bartsch 2009 a). The rostrum is long and slender, apically pointed (perhaps except for A. zagorskisae Otto, 2000), the palps flattened, palps and rostrum are forming a trough. The Australacarus species are expected to feed on body fluids of macrofauna.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE7FF9EFF12A5ABFCADFB61.taxon	materials_examined	Type species. Bathyhalacarus quadricornis Sokolov & Jankovskaja, 1968. Adults. In female and male GP and AP fused. Female GA with two to four pairs of slender pgs, genital sclerites with one to three pairs of sgs. Three pairs of gac arranged in line from about middle of GO posteriad (Fig. 27; Bartsch 1989 b: fig. 26). Ovipositor at rest generally extending beyond GO. Genital spines slender, their number and arrangement not known. Male GO slightly smaller than that of female. Three small pairs of gac in posterior part of GO (Bartsch 1989 b: fig. 24). GO surrounded by 25 – 50 pairs of slender pgs, genital sclerites with five pairs of sgs. Epimeral pores absent in both female and male. Juveniles. One larval and two nymphal stages known. Deuto- and protonymphal GP separated from AP. Deutonymphal GP with two pairs of internal gac and pgs, and with (zero to) two pairs of sgs (Newell 1967: fig. 30; Bartsch 1982 a: figs 28, 41). Protonymphal GP with single pair of gac (Bartsch 2005 a: fig. 16); neither pgs nor sgs present. AE of larva with epimeral pores (Bartsch 2005 a: fig. 17).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE7FF9EFF12A5ABFCADFB61.taxon	discussion	Remarks. This genus is predominately found in the bathyal and abyssal zone of the Atlantic and Pacific Ocean. About a dozen species are described (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE7FF9EFF12A224FAABF814.taxon	materials_examined	Type species. Halacarus drygalskii Lohmann, 1907. Adults. In female and male GP and AP fused. Female GA with 5 – 15 pairs of slender pgs, zero to one pair of sgs and three pairs of large, tube-like gac (Fig. 28; Newell 1984: fig. 201). Ovipositor at rest extending beyond GO. Genital spines slender, number not known. Male GA with more than 100 pgs densely arranged on slightly raised area around GO. Male GO somewhat smaller than that of female; GO in both male and female in ventral position. Each genital sclerite with five short sgs, often two anterior pairs slightly separated from three posterior ones, fourth pair (sgs- 4) stump-like (Newell 1984: fig. 184). Male with three pairs of large internal gac (Fig. 29). AE of adults without epimeral pores. Juveniles. One larval and two nymphal stages known. In nymphs GP separated from AP. Deutonymphal GP with two pairs of large internal gac, one pair of pgs and two pairs minute sgs (Fig. 30; Bartsch 1992 d: fig. 9). Protonymphal GP very small; with one pair of large gac (Fig. 31); pgs and sgs not developed. AE of nymphs without, of larvae with pair of epimeral pores (Bartsch 2004 a: fig. 14).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE7FF9EFF12A224FAABF814.taxon	discussion	Remarks. Almost 20 species are known, often they are found associated with hydrozoans in polar waters but are present also in warm-temperate areas. Records are from shallow water to the deep sea (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE6FF9CFF12A1ACFB5DFE0E.taxon	materials_examined	Type species. Camactognathus grossipes Newell, 1984. Adults. In female and male GP and AP fused. Female GP with three (to four) pairs of slender pgs, one pair of sgs and three pairs of small internal gac (Fig. 32). Ovipositor at rest hardly extending beyond GO. Basal pair of genital spines present but small; antero-apical spines palmate and with dentate edge; shape and number of posteroapical genital spines not known. Male GO smaller than female GO. Two pairs of small gac in posterior part of GO (Bartsch 2013 c: fig. 4), third pair, if present, obscured. Genital sclerites with two pairs of small, setiform sgs. Perigenital setae slender, smooth, about 25 – 50 pairs arranged in two wide rings around GO. Epimeral pores lacking. Juveniles. Larva and protonymph not known. In deutonymph GP and AP fused. GP with two pairs of minute internal gac, two pairs of pgs, but no sgs (Fig. 33; Bartsch 2013 c: fig. 9).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE6FF9CFF12A1ACFB5DFE0E.taxon	discussion	Remarks. A poorly known genus. The three species described are from subtidal sandy deposits, from the coast the southeastern Pacific Ocean (off Chile), the Mediterranean and Black Sea (off Italy and Turkey, respectively) and the Skagerrak (off Sweden) (Newell 1984; Morselli & Mari 1982; Bartsch 1991 a, 2013 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9CFF12A6C3FF04FB89.taxon	materials_examined	Type species. Coloboceras longiusculus Trouessart, 1889. Adults. In female and male GP and AP fused to GA. Female GA with three slender pgs on either side of GO; zero, rarely one sgs on genital sclerites. Three pairs of internal gac arranged in line (Fig. 34). Ovipositor slightly extending beyond GO. With pair of short basal genital spines. Shape and number of apical genital spines not described. Male GO smaller than female GO (Monniot 1962: fig. 1 B). GA with about 25 pairs of slender pgs and five pairs of sgs. Three pairs of internal acetabula situated close together near posterior end of GO. Female and male AE without epimeral pores. Juveniles. With one larval and two nymphal stages, in both nymphs GP and AP separated. Deutonymph with two pairs of internal gac and two pairs of pgs (Fig. 35). Two pairs of pore-like structures immediately adjacent to primordial genital slit may be remnants of sgs. Protonymph with single pair of internal gac, pgs and sgs absent. AE of larva with pair of small epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9CFF12A6C3FF04FB89.taxon	discussion	Remarks. The three species described have been collected in the eastern North Atlantic Ocean (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9CFF12A37CFBB6FA38.taxon	materials_examined	Type species. Coloboceras koehleri Trouessart, 1896.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9CFF12A37CFBB6FA38.taxon	description	Female. GP and AP fused. GA with three pairs of slender pgs but without sgs. Three pairs of internal gac arranged in line (Bartsch 1998 a: fig. 17). Shape of ovipositor and genital spines not known. Epimeral pores lacking. Male and juveniles. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9CFF12A37CFBB6FA38.taxon	discussion	Remarks. Records of the two species described are from the northern and southern Atlantic Ocean. Because of the very slender, pointed rostrum, flanked by elongate palps, and the large pharyngeal plate, these species are expected to attach themselves to macrofauna and feed on body fluids (Bartsch 1998 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9DFF12A10EFD50FF52.taxon	materials_examined	Type species. Copidognathides minutirostris Bartsch, 1976. Adults. Both female and male with GA. Female GA with three pairs of slender pgs and one pair of sgs (Bartsch 1976 b: fig. 8). Single pair of internal gac at about level of mid-GO. Ovipositor short, anteriad hardly extending beyond GO. Genital spines palmate, number not known. Male GA with 10 – 15 pairs of slender pgs, each genital sclerite with four (to five) sgs (Bartsch 1976 b: fig. 10). Single pair of internal gac situated near end of GO (Fig. 36). No marked difference in size of gac between female and male. AE of females and males with epimeral pores. Juveniles. With a single nymphal stage, the protonymph, and a larval stage. In protonymph genital and anal plate plate separated. GP without pgs but with pair of internal gac. Protonymphal and larval AE with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE5FF9DFF12A10EFD50FF52.taxon	discussion	Remarks. The three species described have been collected in shallow water areas of the northeastern Atlantic and southeastern Pacific Ocean (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF9DFF12A637FC29FB61.taxon	materials_examined	Type species. Copidognathus glyptoderma Trouessart, 1888. Adults. In both sexes GP and AP fused. Female GO close to anal cone, in a few mounted (slide) specimens partly overlapping basis of anal sclerites. Female with single pair of internal acetabula in about middle of GO (Figs 37, 38; Newell 1947: figs 198, 224, 1971: fig. 24; Bartsch 2003 a: fig. 8 A, 2006 a: fig. 22), in a few species acetabula somewhat or greatly enlarged, namely in C. acnemus Bartsch 1986, C. cephalocanthus Bartsch 1992, C. laeviusculus Bartsch 1993, C. majorinus Bartsch, 1993, C. mirus Bartsch, 1984 (Bartsch 1984 a: fig. 27, 1986 a: fig. 6, 1992 b: fig. 26, 1993 c: fig. 8 B, 9 G). GA with (2 –) 3 (– 5) pairs of pgs, genital sclerites with single pair of small sgs. Ovipositor at rest extending from slightly to far beyond anterior margin of GO. When at rest, zero to one pair of basal genital spines or papillae and two pairs of apical spines visible through genital sclerites (Figs 37, 38; Bartsch 2013 d: fig. 5). Everted ovipositor apically with four anterior (lateral) and seven posterior spines; their shape spiniform to claw-like and palmate (Figs 39, 40; Bartsch 1977 a: figs 32, 48). Male GA with 4 – 40 pairs of pgs. Male GO similar-sized or somewhat smaller than female GO and in a more ventral position. Genital sclerites with (2 –) 3 – 4 pairs of sgs; often one or two pairs of spur-like sgs in posterior half of sclerites, the other sgs setiform. Single pair of gac in posterior half of GO, similar-sized or slightly smaller than those of female (Newell 1971: fig. 55; Bartsch 1977 b: fig. 133, 2003 a: fig. 7 C, 2006 a: fig. 34). AE of both female and male with epimeral pores. Species living in freshwater often with enlarged pores (if compared with that size in congeners from other habitats) (Bartsch 1979 b: fig. 141, 1999 d: fig. 3), a few inhabitants of marine sandy deposits with enlarged internal lumina, examples are Copidognathus laeviusculus and C. majorinu s (Bartsch 1993 c: figs 8 B, 9 B). Juveniles. A larval and a single nymphal stage (protonymph) known. In both stages AE with pair of epimeral pores. In protonymph GP and AP separated, an exception, the fused plates in C. bunofer Bartsch, 1984 (Bartsch 1984 a: fig. 8); this may be an anomaly. GP of protonymph with single pair of internal gac; pgs and sgs not developed.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF9DFF12A637FC29FB61.taxon	discussion	Remarks. Copidognathus is spread world-wide, in all climatic and depth zones. The genus is the most diverse halacarid taxon, it holds one-third of all species (Bartsch 2004 b, 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF9DFF12A224FE80F9C8.taxon	materials_examined	Type species. Corallihalacarus chilcottensis Otto, 1999.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF9DFF12A224FE80F9C8.taxon	description	Female. Genitoanal plate with two pairs of slender pgs, genital sclerites with single pair of sgs (Otto 1999 c: fig. 2). Number and shape of genital spines and acetabula not known. No epimeral pores present. Male and juveniles. Not seen.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF9DFF12A224FE80F9C8.taxon	discussion	Remarks. A single species is known, collected in the Coral Sea, Queensland, Australia, extracted from coarse sand (Otto 1999 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF82FF12A1BEFCD4FEC6.taxon	materials_examined	Type species. Enterohalacarus minutipalpus Viets, 1938.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF82FF12A1BEFCD4FEC6.taxon	description	Female. Genital and anal plate fused. About 160 slender pgs around GO. GO with three pairs of internal gac (Figs 41, 42). Genital sclerites with two pairs of short, setiform sgs. Ovipositor at rest short. None of individuals examined with ovipositor everted, but genital spines visible through genital sclerites, i. e. three pairs of slender spines in anterior half of GO and several slender spines in posterior part (Fig. 41). Epimeral pores lacking. Male. Not known. Juveniles. In a juvenile stage (deutonymph?) GP and AP separated. GP with about 15 pairs of pgs, two pairs of large internal gac and one (?) pair of sgs (no high magnification possible due to thick layer of mounting medium) (Fig. 43). Larva and protonymph not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFE4FF82FF12A1BEFCD4FEC6.taxon	discussion	Remarks. The single species described was found on and in a sea urchin (Echinoidea) that lived in the Halmahera Sea, Moluccas, at a depth of 430 m (Viets 1938).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF83FF12A787FC40FBFD.taxon	materials_examined	Type species. Halacarus balticus Lohmann, 1889. Adults. Female and male with GA. Female GA with two to four (rarely seven) pairs of pgs, genital sclerites with zero to five pairs of sgs. Three pairs of internal acetabula always distinct, in freshwater inhabiting species enlarged (Viets 1928 a: fig. 49; Bartsch & Gerecke 2011: fig. 1 H). Acetabula arranged in line along genital slit, anterior pair anterior or posterior to level of mid-GO (Fig. 44; Otto 1994: fig. 27). Ovipositor at rest often extending beyond GO. Ovipositor with two basal and eight or ten apical genital spines. Basal pair of genital spines papilli- or setiform. Apical genital spines dissimilar in shape, robust and with tines, slender and spiniform, or reduced to small papillae (Figs 45, 46; Womersley 1937: pl. 6, fig. 12; Bartsch 1998 b: figs 31, 61, 2007 b: fig. 6 G). Male GA with 10 – 50 pairs of pgs and in general five pairs of sgs (rarely less). In the majority of species all three pairs of acetabula internal, arranged along genital slit; in a few species (of the H. capuzinus group) three pairs of acetabula arranged in posterior part of GO, within a fovea that opens to the exterior (Bartsch 1998 b: fig. 48). In freshwater species two pairs of gac posterior to GO, enlarged and external, one pair of gac small, near middle of GO (Viets 1928 a: fig. 48; Bartsch 1998 b: fig. 15). AE without epimeral pores. Juveniles. With larva and two nymphal stages. Nymphs of northern hemisphere species with genital and anal plate fused to a GA (e. g. in the type species H. balticus), most southern hemisphere species with GP and AP separated. Deutonymphal GA with two pairs of pgs, zero to two pairs of sgs and two pairs of gac (Newell 1951: figs 3, 19; Bartsch 1972: figs 25 B, 28 B, 1995 a: fig. 19, 1998 b: figs 24, 41, 63, 82, 101, 1990 c: fig. 137, 1999 c: fig. 3 F). Acetabula of nymphs small and internal, large and internal or large and external (e. g. in H. hyrcanus (Viets, 1928) and H. fontinalis Bartsch & Gerecke 2011 (Bartsch 1998 b: fig. 24; Bartsch & Gerecke 2011: fig. 2 G). Protonymphal GA generally with pair of internal gac; pgs and sgs lacking (Bartsch 1972: figs 25 D, 28 F, 1995 a: fig. 11, 1998 b: figs 44, 85, 1999 c: fig. 3 G). Larva with pair of epimeral pores on AE (Bartsch & Panesar 2000: fig. 3). Larval anal plate often with large ventral part (Bartsch 1972: fig. 25 F, 1998 b: figs 67, 88).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF83FF12A787FC40FBFD.taxon	discussion	Remarks. The genus, with about 50 species, is spread world-wide (Bartsch 2009 a). Several of the species can be assigned to distinct species groups (Bartsch 1997 a). Representatives of the northern Atlantic Ocean groups are not found on the southern hemisphere and vice versa (Bartsch 1997 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF83FF12A3D1FEBAF8A0.taxon	materials_examined	Type species. Halacaroides angustus Bartsch, 1981. Adults. In female and male GP and AP fused. Female GA with one to three pairs of slender pgs (Bartsch 1981 b: figs 13, 24, 2008 c: fig. 4 B) and zero to two pairs of sgs; three pairs of internal gac arranged in line and adjacent in middle of GO (Bartsch 2008 c: fig. 4 F; Pepato et al. 2011: fig. 6 C). Ovipositor at rest extending distinctly beyond GO; when everted five pairs of slender, smooth genital spines visible (Bartsch 2008 c: fig. 4 F). Male GA with 10 – 22 pairs of slender pgs, genital sclerites with three to five pairs of sgs. Male with three pairs of gac in posterior part of GO. Acetabula either adjacent within internal fovea which opens to the exterior (Bartsch 2008 c: fig. 4 G), or one pair internal but two pairs external, directly opening on genital sclerites (Pepato et al. 2011: fig. 6 B). No epimeral pores on AE. Juveniles. Deutonymphal GP with two pairs of internal gac and single pair of pgs (as in female of that species) (Bartsch 2008 c: fig. 5 I); sgs lacking.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF83FF12A3D1FEBAF8A0.taxon	discussion	Remarks. The present records of the genus are from the southern hemisphere (Bartsch 2008 c; Pepato et al. 2011). The four species known are psammobionts. One of the species with the males having their genital acetabula aggregated within a fovea has been collected in a tidal sandy slope which was strongly influenced by freshwater (Bartsch 2008 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF80FF12A071FDFFFD03.taxon	materials_examined	Type species. Agaue hirsuta Trouessart, 1889. Adults. Both female and male with GA. Female with three pairs of moderately large internal acetabula (Fig. 47). Female GA with four to six pairs of pgs, each genital sclerite with four to five sgs. At rest ovipositor short. All genital spines distinctly sclerotized, of brown colour; basal pair of spines long and slender; apically two anterior and at least three posterior pairs of spines present, spines wide and palmate (Fig. 47; Otto 1993: fig. 13). Male GO somewhat smaller than female GO; three pairs of gac adjacent and shorter than in female; GO surrounded by about 50 smooth pgs (Bartsch 1996 c: fig. 64), genital sclerites with five to seven pairs of short spiniform sgs (Otto 1993: fig. 4; Bartsch 1996 c: fig. 65). AE with epimeral pores. Juveniles. With one larval and two nymphal stages. In nymphs genital and anal plate separated. Deutonymphal GP with two pairs of small internal acetabula, two (to three) pairs of pgs and two pairs of minute sgs (Bartsch 1996 c: fig. 80). Protonymphal GP with pair of internal gac; pgs and sgs lacking (Bartsch 1996 c: fig. 83). All juveniles with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFAFF80FF12A071FDFFFD03.taxon	discussion	Remarks. Five species are at present known (Bartsch 2009 a), taken in tropical and warm-temperate areas of the Atlantic, Indian and Pacific Ocean, from tidal and shallow water algae and seagrass. The species are large-sized (idiosoma 550 – 750 µm in length).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF9FF80FF12A5C7FD28F93D.taxon	materials_examined	Type species. Halacarus ctenopus Gosse, 1855. Adults. Genital and anal plates fused. Female GA often with cerotegumental layer close to GO. GA with (1 –) 2 – 15 pairs of slender pgs; species with (one or) two pairs of pgs often with third (rarely fourth) pair of pgs in striated integument anterior to GA. Genital sclerites with three to five pairs of small sgs. Genital acetabula often large, internal; three tube-like pairs present (Newell 1947: figs 98, 129). Acetabula arranged adjacent or posterior pair separated from two anterior pairs (Fig. 48; Newell 1947: fig. 129; Bartsch 2010 b: fig. 4). Ovipositor short, at rest only slightly extending beyond GO, when everted long, slender genital spines seen, namely two pairs of anterior and three pairs of posterior spines (Trouessart 1894: pl. 10, fig. 2 a, a'; Bartsch 2005 a: fig. 20). Male GA with about 30 to more than 150 filiform pgs arranged around GO. Often one or more pairs of pgs outlying; anteriormost pair of pgs either on or anterior to GA. GO smaller than in female and in a more ventral position, somewhat removed from anal cone. Three pairs of gac often slightly shorter than in female, situated adjacent in posterior part of GO (Fig. 49; Newell 1947: figs 95, 128; Bartsch 2010 b: figs 6, 7). Genital sclerites with three to five pairs of short sgs, three posterior pairs of setae generally spur-like. AE of adults without epimeral pores. Juveniles. With larva, proto- and deutonymph. GP and AP in deutonymphs generally separated, rarely fused (Bartsch 1981 a: figs 24, 36, 56, 1993 b: fig. 13 K), GP often small. Deutonymph with two pairs of internal gac, two pairs of pgs, either both on GP, both in striated integument or one pair on GP and one in striated integument anterior to GP, and generally with a pair of sgs, rarely that pair absent (Newell 1947: figs 92, 96, 115; Bartsch 1981 a: figs 4, 24, 36; Pepato & Da Silveira 2013: fig. 2 B). Protonymph with GP and AP separated; GP small, even almost absent; one pair of internal acetabula and a single pair of minute setae within GP or in striated integument, situated very close to acetabula (Bartsch 1981 a: fig. 6, 2002: fig. 46, 2007 b: fig. 9 G; Pepato & Da Silveira 2013: fig. 2 H). Nymphs without, larva with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF9FF80FF12A5C7FD28F93D.taxon	discussion	Remarks. The majority of the presently known 76 species (Bartsch 2009 a, 2011 b; Pepato & Da Silveira 2013) are rather large-sized, the length of their idiosoma between 400 and 1500 µm. Records of the genus are from all oceans and depth zones from the waterline to deep-sea basins. Most of the species are epibionts on various substrata, only a few species are psammophilous.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF9FF81FF12A011FB4DFE2A.taxon	materials_examined	Type species. Agaue chitonis Brucker, 1897. Adults. AE of adults without epimeral pores. Both female and male with GA. Female GA with up to 12 – 13 pairs of pgs; and zero to one sgs on each genital sclerite (Bartsch 1986 b: fig. 5). Shape and number of genital spines not known. Male with more than 100 slender pgs very densely packed on a slightly raised area around GO (Fig. 50). Genital sclerites with five pairs of very short sgs, these stump-like and apically slightly spinose (Fig. 51). Acetabula internal, posterior-most pair tube-shaped, two anterior pairs cupuliform (Fig. 52). Juveniles. With deuto- and protonymphal stage, no records of larva published but this instar certainly present. In both nymphs GP small, separated from AP. Deutonymphal GP with two pairs of gac and single pair of pgs; sgs lacking (Bartsch 1986 b: fig. 15). Protonymphal GP very small, with one pair of gac; pgs and sgs lacking (Viets 1959).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF9FF81FF12A011FB4DFE2A.taxon	discussion	Remarks. Three species are described, all three are from New Zealand (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A51FFAFFFD69.taxon	materials_examined	Type species. Hamohalacarus subterraneus Walter, 1931.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A51FFAFFFD69.taxon	description	Female. GP with three to four pairs of pgs anterolateral to GO and three pairs of external gac in posterolateral parts of GP (Walter 1931: fig. 2). GO large, genital sclerites with one pair of sgs. AE with pair of epimeral pores. Male and juveniles. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A51FFAFFFD69.taxon	discussion	Remarks. Inhabitant of freshwater. The single record is from a cave in Indiana, US (Walter 1931).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A45DFBF8FBB4.taxon	materials_examined	Type species. Himejacarus morimotoi Imamura, 1957.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A45DFBF8FBB4.taxon	description	Male. GO in middle of GP, surrounded by more than 80 pgs. Four pairs of external gac in posterolateral parts of GP (Imamura 1957: fig. 1 a). Male AE with pair of epimeral pores. Female and juveniles. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF81FF12A45DFBF8FBB4.taxon	discussion	Remarks. Inhabitant of freshwater. Recorded from Japan (Imamura 1957).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF87FF12A364FEE0FDE6.taxon	materials_examined	Type species. Aletes setosus Lohmann, 1889. Adults. Female GP delicate and often in form of pair of crescentic plates on either side of GO, not or only slightly longer than GO and not distinctly delimited from striated integument. Female genital area with three (rarely four) pairs of pgs, anterior pair in striated integument, anterior to GO, following two pairs level with and posterior to GO, respectively, in margin or outside GP. Anterior and posterior edge of genital foramen often enforced by internal pregenital and postgenital sclerites (Fig. 53). Genital sclerites with one to two pairs of sgs. Female with two or three almost equal-sized internal tube-like gac (Figs 54, 56), or two pairs of distinct, tube-like and one pair of small gac (Fig. 53; Viets 1939 b: fig. 21; Newell 1947: figs 55, 80; Bartsch 1974 b: fig. 2 b; Abé 1996 a: figs 4 A, 8 A, 16 A, 20 A, 1996 b: fig. 2 A) (the posterior markings illustrated in Newell 1947: fig. 59 are no acetabula). Ovipositor short, both at rest and when everted. Genital spines well-sclerotized, rather wide and palmate, generally ending with several tines; 10 – 11 spines present, four in anterior and six to seven in posterior position (Bartsch 1975 a: figs 10 b, 11, 1975 b: fig 103, 2000: fig. 1 D; Newell 1984: fig. 42). GP in male larger than in female, with about 30 – 100 perigenital setae, these often arranged in an inner and outer ring around GO and inserted on GP, rarely in striated integument outside GP. Setae generally slender and smooth, in a few species some of anterior setae of inner ring short, bristle-like or spiniform, namely in I. hutchinsoni Newell, 1947 and I. uniscutatus (Viets, 1939) (Fig. 60; Newell 1947: fig. 76). Genital sclerites with four (rarely three) pairs of sgs, these setiform, rarely flattened and foliate or spur-like. Acetabula generally slightly smaller than in females and situated in posterior part of GO or even posterior to GO (Fig. 60). As in female, male GO with either two to three pairs of large almost equal-sized gac or two large pairs and one anterior small pair (Fig. 56; Viets 1939 b: fig. 21; Newell 1947: fig. 76, 1984: fig. 37; Abé 1996 a: figs 4 B, 16 B; 1996 b: fig. 2 B; Bartsch 2003 a: fig. 2 M). Acetabula generally internal, in two species (I. hutchinsoni, I. uniscutatus) two pairs of external acetabula present (Newell 1947: fig. 76; Bartsch 1979 b: fig. 13, 2003 c: fig. 3 F). Juveniles. With four juvenile stages, one larva and three nymphs (proto-, deuto-, tritonymph). Nymphal genital and anal plate in some species separated in others fused. Tritonymph with a pair of small sgs and two pairs of pgs, one pair in striated integument anterior to GP, one pair on or close to GP. Genital region with two or three pairs of almost equal-sized acetabula (Fig. 55, 57; Newell 1947: fig. 81; Bartsch 1972: fig. 18 G, 2005 c: fig. 14, 2009 b: figs 5 F, 7 G; Abé 1996 b: fig. 2 C) or with pair of large anterior acetabula, small, short middle pair, more or less adjacent to anterior pair of gac, and slender posterior pair (Bartsch 1972: fig. 21 D, 1975 b: figs 81, 100, 121; Abé 1996 a: figs 16 C, 23 A). Deuto- and protonymph without sgs. Deutonymph with single pair of pgs situated level with gac and on or in margin of GP. Majority of deutonymphs with two pairs of gac, either equal-sized (Abé 1996 b: Fig. 2 D) or with small anterior and large posterior pair of gac (Bartsch 1972: fig. 21 C, 1975 b: figs 82, 101, 120; Abé 1996 a: figs 4 C, 23 B), or with single pair of gac (Fig. 58; Newell 1947: p. 80; Bartsch 1972: p. 191, fig. 18 D). Protonymph with single pair of internal gac; pgs and sgs lacking (Fig. 59; Bartsch 1972: fig. 21 B, 1975 b: figs 83, 102, 119; Abé 1996 a: fig. 23 C, 1996 b: fig. 2 E). Larva with pair of epimeral pores (Bartsch 1974 b: fig. 1 a, 2 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF8FF87FF12A364FEE0FDE6.taxon	discussion	Remarks. At present 29 species are known. The species live in a zone more or less regularly emerged; all feed on algae. The genus is spread world-wide but three different lineages have been separated on the basis of their character combinations (Abé 2001; Bartsch 2010 a). The species of each lineage are concentrated within a geographical area which roughly can be attributed to the temperate northern Atlantic and Pacific Ocean (ca 75 ° N to 25 ° N), the tropics (ca 25 ° N to 25 ° S) and the temperate southern Pacific and Indian Ocean (ca 25 ° S to 55 ° S). The different number and shape of the genital acetabula are in concordance with these three groups. Adults and tritonymphs from the southern temperate zone have two pairs of acetabula, those from the tropics three pairs, and those from the northern temperate zone generally two pairs of large-sized and one pair of small acetabula. Exceptions are the North Atlantic species I. uniscutatus and I. hutchinsoni which have two pairs of acetabula; populations of both can survive in low saline brackish water. The deutonymphs of the southern temperate zone have a single pair of gac, those from the tropics two equal-sized pairs and species from the northern temperate zone a large and a minute pair of acetabula, again with the exception of I. uniscutatus which bears a single pair of acetabula.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFEFF87FF12A5ABFBACFAA9.taxon	materials_examined	Type species. Halacarus wackeri Walter, 1914. Adults. In female genital- and anal plate contiguous or partly fused. Female GO near posterior margin of genital plate and covered by large genital sclerites. Acetabula in external position; arranged along lateral margins of genital plate; 4 – 12 pairs present. Female with three to ten pairs of slender pgs and one to four pairs of sgs; GO in subterminal position (Bartsch 2006 c: fig. 5 - 15 b). Ovipositor short and slender. Genital spines delicate, short and spiniform; number not known. In male GP and AP fused. Arrangement of external acetabula same as in female. Male GO much smaller than in female and in a ventral position (Bartsch 2006 c: fig. 5 - 15 c). Perigenital setae slender, 17 – 30 pairs surrounding GO. Genital sclerites with three pairs of small subgenital setae. AE in both female and male with epimeral pores. Juveniles. With two nymphal stages, deutonymph and protonymph. In both nymphs GP and AP fused. Genitoanal plate of deutonymph with two to six pairs of pgs; zero to two pairs of sgs and three to eight pairs of external gac, the latter arranged as in adults. Protonymph with two to three pairs of gac; pgs and sgs lacking. Larva with pair of large epimeral pores (Bartsch 2013 a: fig. 2 f).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFEFF87FF12A5ABFBACFAA9.taxon	discussion	Remarks. Limnohalacarus is a cosmopolitan genus; slightly more than a dozen species have been described (Bartsch 2013 a). The females do not deposit the eggs in the substratum inhabited but attach them to the hind legs. This way of egg deposition may be correlated with a reduction of the genital spines.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFEFF87FF12A29DFD06F830.taxon	materials_examined	Type species. Walterella weberi Romijn & Viets, 1924.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFEFF87FF12A29DFD06F830.taxon	description	Female. All ventral plates fused, AP included. Area of GP with two to seven pairs of slender pgs, mostly four or five pairs of setae present. Female GO in posterior part of GP; each genital sclerite with zero to three sgs and zero to three external gac; no acetabula outside genital sclerites. Ovipositor short, at rest anteriad not extending beyond GO. Everted ovipositor showing a basal pair of small spines and five apical pairs of sclerotized genital spines (Bartsch 1975 d: fig. 51). AE with pair of epimeral pores. Male. Not known. Juveniles. With deutonymph, protonymph and larva. In both deutonymph and protonymph genital and anal plate fused to a genitoanal plate, in larvae genital plate lacking. Deutonymph with two pairs of gac; single pair of pgs in anterior part of GA; sgs lacking (Bartsch 1975 d: fig. 50). Protonymph with single pair of gac; without pgs and sgs. All juveniles with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFEFF87FF12A29DFD06F830.taxon	discussion	Remarks. Two Lobohalacarus species are known, one with several subspecies (Bartsch 2008 a). Lobohalacarus is a cosmopolitan genus, it lives in freshwater, is regularly found in groundwater-fed habitats, but also in surface waters, even in coastal brackish water.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF84FF12A787FC1DFC6D.taxon	materials_examined	Type species. Leptognathus falcatus Hodge, 1863. Adults. In female and male GP and AP fused. Female GO same or somewhat larger than that of male, in both GO generally in almost similar position. Female GA of marine species with three pairs of internal gac, these often rather small, rarely large (Viets 1939 a: fig. 7; Bartsch 1986 d: fig. 19). Females of freshwater species with two pairs of external acetabula in posterior part of genital sclerites (Petrova 1969: figs 2 b, 5 b). Female GA with 6 – 37 pairs of slender pgs; each genital sclerite with four subgenital setae. Ovipositor short, with 12 genital spines, one basal and five apical pairs, the latter in 2 + 3 arrangement (two anterior and three posterior pairs). Genital spines of L. gaussi Lohmann, 1907 similar-sized, palmate, each ending with numerous tines (Bartsch 1979 a: fig. 29). Male GA with 25 – 40 pairs of slender pgs, these arranged densely around GO. Each genital sclerite with four short sgs. Genital acetabula in general small, three pairs adjacent in posterior part of GO (Viets 1939 a: fig. 8; Bartsch 2005 b: fig. 1 D). In a few freshwater inhabiting species acetabula external, situated on genital sclerites (Petrova 1969: figs 1 b, 4 b). Adults without epimeral pores. Juveniles. With a larval and two nymphal instars. In deuto- and protonymph GP separated from AP. Deutonymphal GP with two to five pairs of pgs, two pairs of sgs and two pairs of internal gac (Imamura 1968: fig. 5; Bartsch 1979 a: fig. 37, 2005 a: fig. 36, 2005 b: fig. 2 F). Protonymph with a pair of internal acetabula and, immediately posterior to the level of acetabula, with a single pair of small setae close to primordial genital slit (Fig. 61); no further setae present. Larva with tube-like epimeral pores (Bartsch 2007 b: fig. 10 C).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF84FF12A787FC1DFC6D.taxon	discussion	Remarks. Thirty-one species are known from marine habitats, another five have been found in fresh and low salinity brackish water areas. The marine species are spread world-wide and inhabit all depth zones from the low water edge to the deep sea (Bartsch 2009 a). Records of the freshwater species are from the circum-Mediterranean, from areas once being adjacent or covered by the Paratethys (Bartsch 1996 g)	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF84FF12A321FD04F910.taxon	materials_examined	Type species. Acanthopalpus hirsutus Makarova, 1978.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF84FF12A321FD04F910.taxon	description	Female. Genital and anal plates fused. GA with three pairs of pgs, each genital sclerite with two sgs (Bartsch 1978: fig. 26). Three small pairs of internal gac, two situated in middle part of GO, one pair in posterior part (Fig. 62). Ovipositor at rest hardly extending beyond GO. Basis of ovipositor with pair of spines, apex with ten moderately sclerotized spines (Fig. 63), these four anterior and six posterior spines ending with bifid tip. In ovipositor at rest pair of basal spines and two anterior pairs of apical spines visible through genital sclerites, the former pair near anterior margin of GO, the latter near posterior margin. AE without epimeral pores. Male. Not known. Juveniles. With two nymphal and one larval stage. Genital and anal plates fused in both proto- and deutonymphs. Deutonymph with two pairs of pgs, two pairs of sgs, and two pairs of internal gac (Bartsch 1978: fig. 33). GA of protonymph with one pair of internal gac (Bartsch 1978: fig. 34); pgs and sgs lacking. AE with remnants of epimeral pores. Larval AE with pair of small epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF84FF12A321FD04F910.taxon	discussion	Remarks. Two species have been described. The records are from cold-temperate to Arctic waters of the northern Atlantic and Pacific Ocean (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF85FF12A1F6FDB7FD2E.taxon	materials_examined	Type species. Rhombognathus armatus Lohmann, 1893. Adults. In female GP reduced in size, separated from AP. GP only slightly larger than GO, anterior pair of pgs on or in margin of GP, two following pairs in striated integument. Genital sclerites lack sgs. Anterior-most of three pairs of internal gac more slender than following pairs and adjacent or fused to second pair (Bartsch 1975 a: fig. 14 a, 2003 c: fig. 6 M); that anterior pair may be obscured in ventral aspect. Pairs of gac at and posterior to the level of middle of GO, posterior pair internally extending posteriad beyond GO. Ovipositor short, both at rest and everted. Genital spines with numerous delicate spicules included in a membrane. Everted ovipositor with four pairs of genital spines. Two antero-apical pairs and one of postero-apical pair recognizable when ovipositor at rest (Bartsch 1975 a: fig. 14 a). In male GP and AP fused. Length of male GO similar to that of female. GA with 30 – 40 pairs of bristle-like, smooth pgs, genital sclerites with three pairs of small, rather spiniform sgs. Acetabula internal, situated adjacent in posterior part of GO (Fig. 64); gac somewhat smaller than in female. As in female, anterior pair of acetabula more narrow and fused with second pair (Bartsch 1972: fig. 10, 2003 c: fig. 6 I). Adults without epimeral pores. Juveniles. With one larva and two nymphs. Genital and anal plate fused in both deutonymph and protonymph. Deutonymph with two pairs of internal gac, two pairs of pgs, no sgs (Bartsch 2003 c: fig. 6 G). Protonymph with single pair of gac; pgs and sgs not developed (Bartsch 2003 c: fig. 6 F). Larva with pair of tube-like epimeral pores (Bartsch 1974 b: fig. 1 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFDFF85FF12A1F6FDB7FD2E.taxon	discussion	Remarks. Two species have been described, both are common in tidal green algal belts of the northern Atlantic and Arctic Sea (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFCFF85FF12A5E3FD36F981.taxon	materials_examined	Type species. Mictognathus werthelloides Newell, 1984. Adults. GP and AP fused in both female and male. Female GA with three (to four) pairs of pgs but no sgs. Ovipositor rather short, at rest slightly extending beyond GO. With three pairs of internal gac, anterior pair just anterior to level of mid-GO (Fig. 65). Genital spines short and spiniform, their number not known. Male GO somewhat smaller and distance to posterior margin of GP larger than in female. GP with about 13 – 28 pairs of slender pgs, arranged rather densely around GO. Each genital sclerite with three short, seti- or spur-like sgs. Two pairs of internal gac in posterior half of GO (Newell 1984: fig. 592). According to Newell (1984: figs 593, 596), AE of adults with epimeral pore-like structure, but epimeral pores not mentioned by Bartsch (1992 a) and Otto (2001). Juveniles. At present only deutonymphal instar known. GP separated from AP; GP with two pairs of gac and one pair (Fig. 66; Bartsch 1992: p. 89), one and a half or two pairs (Newell 1984: fig. 594, p. 215) of pgs in posterior part of GP; sgs lacking.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFCFF85FF12A5E3FD36F981.taxon	discussion	Remarks. The three species known are from the southern hemisphere (Bartsch 2009 a). According to Newell (1984: p 215) the GP of the deutonymph bears two pairs of pgs, but according to the illustration (Newell 1984: fig. 594) there is one seta in one half and two in the other. The two setae are in an unusual position, namely almost adjacent, whereas in the majority of halacarid nymphs with two pairs of perigenital setae these are widely separated (cf. Figs 4, 22, 35). The presence of two pairs of pgs is expected to represent an anomaly. Both deutonymphs studied by the author have a single pair of pgs, one of the deutonymphs is from about 57 ° S, 27 ° W, the other from 65 ° S, 64 ° W.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFCFF8AFF12A144FB01FE9A.taxon	materials_examined	Type species. Soldanellonyx parviscutatus Walter, 1917. Adults. In female genital and anal plate separated. GP with three to ten pairs of slender pgs and, posterolateral to GO, three to nine pairs of external gac. Each genital sclerite with two to three (to six) sgs (Bartsch 2006 c: fig 5 - 16 b). Ovipositor short, basally with pair of spiniform genital spines, apically with five pairs of similar-sized spines, two pairs in anterior and three pairs in posterior position (Viets 1933 a: fig. 10). In males GP and AP fused. GA with about 70 – 80 slender pgs. GO smaller and in a more ventral position than in female; three to five pairs of gac arranged as in female (Bartsch 2006 c: fig 5 - 16 e). Each genital sclerite with two or three short sgs. In both sexes AE with pair of epimeral pores, shape of pores same as that of genital acetabula. Juveniles. With a larval and two nymphal stages. In nymphs GP and AP separated. GP of deutonymph with two pairs of gac and pgs and one pair of sgs. Protonymph with single pair of gac; pgs and sgs lacking. Nymphs and larva with epimeral pores, their shape same as those of adults.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFFCFF8AFF12A144FB01FE9A.taxon	discussion	Remarks. Records of the three Parasoldanellonyx species at present known are from the Palaearctic and Nearctic zone (Bartsch 2009 a). They live in freshwater, in groundwater-fed ponds and moist areas.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A66FFA88FD69.taxon	materials_examined	Type species. Parhalixodes travei Laubier, 1960.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A66FFA88FD69.taxon	description	Male (?). Genital and anal plates contiguous (Laubier 1960: figs 1 b, 2 d). GP with single pair of pgs. Genital acetabula not mentioned in the description. Female. Not known. Juveniles. A single juvenile stage known, expected to be a protonymph. AE with pair of epimeral pores. GP and AP contiguous or fused. GP with a pair of gac; sgs absent; pair of pores in striated integument (Newell 1971: fig. 77) may be remnants of pgs.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A66FFA88FD69.taxon	discussion	Remarks. Two species have been described, one from the Mediterranean, the other from the southeastern Pacific Ocean. The species are expected to be at least temporarily ectoparasitic (Laubier 1960; Newell 1971).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A45DFDC9FB60.taxon	materials_examined	Type species. Agaue aculeata Trouessart, 1896. Adults. In female and male GP and AP fused. Female GA with three pairs of pgs; each genital sclerite with three sgs (Bartsch 1986 e: fig. 13). Three pairs of gac arranged in line from level of mid-GO posteriad. Ovipositor short, at rest not extending beyond GO. Number and shape of genital spines not known. Male GO smaller and in a more ventral position than female GO. Male GA with eight pairs of pgs; genital sclerites with five pairs of spur-like sgs (Bartsch 1986 e: fig. 22). Female and male AE with large epimeral pores. Juveniles. At present only the deutonymphal instar known. In deutonymph GP and AP separated; GP with two pairs of pgs, one pair of sgs and two pairs of internal gac (Bartsch 1986 e: fig. 32). AE with large epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A45DFDC9FB60.taxon	discussion	Remarks. A single species is known, it is recorded from the northeastern Atlantic and Mediterranean (Trouessart 1896 a; Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A226FC04F8EA.taxon	materials_examined	Type species. Peregrinacarus reticulatus Bartsch, 1999. Adults. Genital and anal plate fused in both female and male. Female GA with four to six pairs of slender pgs, each genital sclerite with zero to one sgs. GO with three pairs of internal gac arranged in line. Posterior-most pair larger than anterior ones; the former situated near end of GO (Bartsch 2001 b: fig. 5). Ovipositor at rest extending beyond GO. Apex of ovipositor with two anterior pairs of spiniform, smooth genital spines; shape and number of posterior pairs of spines not known. Male GO somewhat smaller than that of female and removed from end of GP. GA with about 40 slender pgs and five to six pairs of sgs. Acetabula arranged in line; two anterior pairs small, posterior-most pair slightly enlarged (Bartsch 1999 b: fig. 4). AE of adults without epimeral pores. Juveniles. With one larval and two nymphal stages. In nymphs GP and AP separated. Deutonymphal GP with two pairs of pgs, zero to two pairs of sgs and two pairs of large internal gac (Bartsch 1999 b: fig. 19, 2001 b: fig. 18). Protonymphal GP with single pair of large gac, internal as in deutonymph; pgs and sgs lacking (Bartsch 1999 b: fig. 23, 2001 b: fig. 21). Larva with tube-like epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF3FF8AFF12A226FC04F8EA.taxon	discussion	Remarks. The two species at present known are from southern hemisphere coldwater areas, from brackish to fresh water rather close to the sea (Bartsch 1999 b, 2001 b; Pešić et al. 2010).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF8BFF12A787FB3BFB89.taxon	materials_examined	Type species. Phacacarus flavellus Bartsch, 1992. Adults. Genital and anal plate fused in both female and male. Female with two pairs of pgs; sgs lacking (Bartsch 1992 c: fig. 2). With single pair of gac, situated in about middle of GO (Fig. 67). Ovipositor very short, at rest not extending beyond GO. Genital spines small, their number and shape not known. Male GA with two pairs of slender pgs; GO large, sgs absent (Bartsch 1994 a: fig. 2). AE with pair of epimeral pores. Juveniles. At present only larval but no nymphal stage found. AE of larva with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF8BFF12A787FB3BFB89.taxon	discussion	Remarks. A single species is known which has been collected on the western coast of Australia Bartsch (1992 c). Phacacarus flavellus is expected to have a special mode of living. At present known are the female, male and larva but no nymphs. The species has several unusual characters. The females have large, solid, pigmented dorsal and ventral plates, the legs bear large lamellae. The males have very delicate, unpigmented plates and their legs lack the wide lamellae. The larva has an unusual minute PD, it is just a sclerite surrounding the posterior pair of gland pores. In contrast to most halacarid species, Phacacarus has an unusual short gnathosoma and rostrum but solid chelicerae and a large pharyngeal plate that extends posteriad far beyond the gnathosoma. In the related genus Copidognathus, the shape of the legs is almost the same in female and male, there is no striking difference in the pigmentation, thickness and shape of the dorsal plates, and the posterior dorsal plate of the larvae is smaller than in adults but never as miniaturized as in Phacarus larvae. In both genera the legs of the larvae never have such wide lamellae as present in females. Phacacarus flavellus was found amongst coralline algae, more details are not known. Because of the reduced and delicate plates, the males and larvae are expected not to live on and amongst the algae, as assumedly the females do, but more or less inside a cavity, perhaps in the coralline algae, gnawed with those solid chelicera. Though speculative, the nymphal instar (s) may have been reduced in the course of this life-style.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF8BFF12A37CFF1FF958.taxon	materials_examined	Type species. Halacarus alpinus Thor, 1910. Adults. Anal and genital plate in female separated (P. alpinus) or fused (P. gallicus) (Angelier 1952: fig. 2; Green 1954: fig. 2 A; Bartsch 2006 c: fig. 5 – 10 a, fig. 5 – 11 b). GP with 4 – 15 pairs of slender pgs but no sgs. GO in posterior part of GP. Each genital sclerite with three to nine external acetabula. Ovipositor short, at rest slightly extending beyond GO. Basal pair of genital spines smooth, ten apical spines wide, bifid. Apical spines arranged in two anterior and three posterior pairs (Bartsch 1973 b: fig. 8). Male GP and anal plate contiguous or fused. GP with 10 – 40 pairs of pgs. GO slightly removed from posterior margin of GP. Three to six pairs of external gac situated either on genital sclerites (?) (Migot 1926: fig. 2;) or posterior to GO (Bartsch 2006 c: fig. 5 – 10 b). Genital sclerites with single pair of sgs. No epimeral pores present. Juveniles. With one larval and two nymphal stages. In nymphs genital and anal plate separated. GP of deutonymph with two to seven pairs of external gac, two pairs of pgs but no sgs (Bartsch 1973 b: fig. 9). GP of protonymph with two, rarely three pairs of external gac; pgs and sgs not developed. Larva with epimeral pores (Bartsch 1973 b: fig. 11).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF8BFF12A37CFF1FF958.taxon	discussion	Remarks. A freshwater genus which at present includes two species, one seems to be restricted to European waters, the other to be a cosmopolitan (Bartsch 2009 a). Most records are from surface waters (lakes, ponds, ditches).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF88FF12A02EFD1BFE56.taxon	materials_examined	Type species. Leptognathus violaceus Kramer, 1879.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF88FF12A02EFD1BFE56.taxon	description	Female. Genital and anal plate fused. Female GO in ventral position. Genital plate with three pairs of pgs. Two pairs of gac external, on genital sclerites, one rather inconspicuous pair inside genital cavity (Bartsch 2007 a: fig. 27); sgs lacking. Ovipositor short; with one pair of setiform, slightly spinose basal genital spines and five pairs of short apical spines; of the latter three posterior pairs tri- or quadrifid stumps, two anterior pairs slightly more slender and longer than posterior spines (Bartsch 2007 a: fig. 28). AE without epimeral pores. Male. Not known. Juveniles. With one larval and two nymphal stages. Deuto- and protonymph with genital and anal plate fused. Deutonymph with two pairs of external gac, two pairs of pgs, but without sgs (Bartsch 2007 a: fig. 18). Protonymph with single pair of gac; pgs and sgs lacking (Bartsch 2007 a: fig. 10). Protonymph and larva with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF2FF88FF12A02EFD1BFE56.taxon	discussion	Remarks. Freshwater genus. At present a single species is known which is wide-spread on the northern hemisphere, in lenitic surface waters (Bartsch 2007 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF1FF89FF12A06DFEC9FC93.taxon	materials_examined	Type species. Aletes pascens Lohmann, 1889. Adults. Both female and male with genitoanal plate. Genital opening of female close to, that of male slightly removed from posterior margin of GP. Genital acetabula internal, three pairs present, in female posterior pair largest in size; anterior-most pair adjacent to or fused with middle pair of acetabula (Fig. 68). Female GA with three pairs of slender pgs; genital sclerites large, in ventral aspect often concealing anal plates; sgs lacking. Ovipositor short, at rest not extending beyond GO. Genital spines slender, hardly sclerotized. Ovipositor with four pairs of spines (Trouessart 1894: pl. 10, 3 b, b'; Bartsch 1975 a: fig. 12 b). Male GO slightly smaller than female GO; genital sclerites weakly delimited, not as operculiform as in female. GO surrounded by about 15 – 40 pairs of pgs; pgs slender and setiform or short, rather bristle-like, in some species (e. g. R. pascens) posterior pairs of setae short and flattened (Bartsch 1972: fig. 6). Genital sclerites with three pairs of short seti- to spur-like sgs. Three pairs of gac situated adjacent in posterior half of GO (Newell 1947: fig. 26; Bartsch 1972: fig 7, 9, 11 c, 2003 c: fig. 9 I). Acetabula slightly unequal in size. Adults without epimeral pores. Juveniles. With one larva and two nymphs. In proto- and deutonymph genital and anal plate fused. GA of deutonymph with two pairs of internal gac, two pairs of pgs but no sgs (Bartsch 2003 c: fig. 9 G). GA of protonymph with a pair of internal acetabula; pgs and sgs lacking. In contrast to nymphs AE of larva with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF1FF89FF12A06DFEC9FC93.taxon	discussion	Remarks. According to Bartsch (2009 a) there are six valid species. Rhombognathides is spread in the northern Atlantic and Arctic Sea where it is commonly found amongst shallow water algae, often it is present in dense populations.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF0FF8EFF12A477FA85FE49.taxon	materials_examined	Type species. Pachygnathus notops Gosse, 1855. Adults. In most of females GP and AP contiguous or partly fused, in a few species these plates separated. GO in posterior part of GP; with 1 – 45 pairs of slender pgs around GO and two pairs of sgs, rarely a single pair (e. g. in R. peltatus Viets, 1939, cf. Bartsch 1996 f: fig. 31). Acetabula internal, in general three pairs almost equal-sized gac present, rarely two pairs (e. g. in R. intermedius Schulz, 1933, R. neotenus Abé, 1996, R. peltatus Viets, 1939) (Abé 1996 a: fig. 50 A; Bartsch 1975 b: fig. 8). In two species (R. amplus Bartsch 2013, R. bulbosus Bartsch 2005), a single pair of gac distinctly recognizable (Bartsch 2005 c: fig. 22, 2013 e: fig. 1 h). Ovipositor short, both at rest and everted, at rest hardly extending beyond GO. When everted, ovipositor basally with pair of delicate papillae (may be vestigial), apically with five pairs of sclerotized, palmate genital spines, each ending with three to nine spikelike tines (Bartsch 1975 a: figs 8 a, 9 b, 1975 b: fig. 46, 1975 c: figs 4, 18, 2000: fig. 21 C). In males GP and AP generally fused, also in species in which females have separate plates. Male GO often smaller and in a more ventral position than female GO. Area representing GP with 7 – 25 pairs of pgs, in many species setae plumose and arranged trapezoidally, else setae smooth. Each genital sclerite with two small sgs, these generally setiform, rarely plumose (Abé 1996 a: figs 25 B, 29 B, 33 B, 37 B, 43 D, 46 D, 59 E; Bartsch 2013 e: fig. 1 d). GO normally with three pairs of internal gac, except for e. g. the five above mentioned species, in these, as in their females, two pairs or a single pair of acetabula recognizable (Bartsch 1975 b: figs 9, 24, 1975 c: fig. 27, 2003 c: fig. 12 I, 2013 e: fig. 1 c). Acetabula in males often more contiguous than in females and situated near posterior end of GO (except e. g. R. leurodactylus Krantz, 1976, cf. Abé 1996 a: fig. 43 D and C). All stages, adults and juveniles, with tube-like epimeral pores. Juveniles. Majority of species with three nymphal and one larval stage. Tritonymphal GP and AP either fused or separated, GP and AP of deuto- and protonymph generally fused. Tritonymphal GP with two pairs of pgs, one pair of sgs and, in the majority of species, with three pairs of equal-sized internal gac. Tritonymphs of R. amplus and R. bulbosus with two large pairs and a median short, slender pair of gac (Bartsch 2005 c: fig. 37, 2013 e: fig. 3 c), these nymphs of R. cyrtonotus Bartsch, 2000, R. intermedius, R. neotenus and R. peltatus with two pairs of gac (Bartsch 1975 b: fig. 21, 1975 c: fig. 24; Abé 1996 a: fig. 53 A). Deutonymphal GP with two pairs of internal gac, equal-sized apart from e. g. R. amplus and R. bulbosus. Deutonymphs of these two species with minute anterior and tube-like posterior pair of acetabula (Bartsch 2013 e: fig. 3 e). Deutonymphal GP without pgs and sgs. Protonymph with single pair of gac; pgs and sgs lacking. Larvae with pair of tube-like epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF0FF8EFF12A477FA85FE49.taxon	discussion	Remarks. In a few species, the deutonymphal stage seems to be suppressed. Of both R. intermedius and R. peltatus numerous individuals, collected in different seasons, have been studied, larva, protonymphs (with fivesegmented leg IV and single pair of gac), tritonymphs (with two pairs of pgs and one pair of sgs) and adults were present in the samples but no deutonymphs (Bartsch 2003 c). In these two species adults have no more than two pairs of gac. Because of the reduced number of gac in the tritonymphs of R. cyrtonotus Bartsch, 2000 and R. neotenus, these species, too, are expected to have lost the deutonymphal instar. In the majority of the deuto- and tritonymphs the two or three pairs of acetabula are similar in size, but in R. amplus and R. bulbosus the size is different and the situation resembling that of Isobactrus species of the northern temperate zone. The genus Rhombognathus is spread world-wide, it includes more than 100 species (Bartsch 2009 a, d, 2013 e; Abé & Fernandes 2011, Abé & Etamadi 2014). The species are algivorous, hence restricted to the photic zone.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8EFF12A53BFBFBFBB5.taxon	materials_examined	Type species. Porohalacarus uniscutatus Bartsch, 1982.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8EFF12A53BFBFBFBB5.taxon	description	Female. Ventral plates fused. Genital acetabula external, three pairs situated on genital sclerites (Bartsch 1982 b: fig. 3, 2013 b: fig. 1 b). Genital and anal plates contiguous or fused. Genital plate with two to three pairs of slender pgs; sgs lacking. Ovipositor at rest short, not extending beyond GO; basal pair of genital spines in middle of GO, spines wide but not intensely sclerotized. Anterior pair of apical spines flattened, slightly palmate. Number and shape of the other apical spines not known. Area of AE without epimeral pores. Male. Not known. Juveniles. With deuto-, protonymph and larva. In deuto- and protonymph genital plate and anal plate separated or partly fused. Deutonymph with two pairs of gac, a single pair of pgs; sgs lacking (Bartsch 2013 b: fig. 2 f). Protonymph with pair of gac; pgs and sgs lacking (Bartsch 2013 b: fig. 2 g). Nymphs without, larva with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8EFF12A53BFBFBFBB5.taxon	discussion	Remarks. Ropohalacarus is spread in fresh water. The two species described are primarily inhabitants of subterranean sandy deposits. The genus is wide-spread (Bartsch 2009 a, 2013 b).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8EFF12A399FC57F884.taxon	materials_examined	Type species. Scaptognathides planus Monniot, 1972. Adults. In both female and male genital and anal plates fused. Female GA with two pairs of pgs, and one to zero sgs on each genital sclerite. Two pairs of partly fused internal gac in posterior to middle part of GO (Fig. 69; Bartsch 2003 d: fig. 7 I). Ovipositor at rest short, not extending beyond anterior margin of GO; when everted five pairs of lamellar, weakly sclerotized genital spines recognizable (Bartsch 2003 d: fig. 7 D). Male GO smaller than female GO and distinctly removed from AP. GA with up to 16 pairs of slender pgs, one pair of setae in anterior half of GA, the others lateral and posterior to GO, arranged around a genital groove. Each genital sclerite with three short, setiform sgs. Genital acetabula in posterior part of GO, one (Monniot 1972: fig. 2 A), generally two pairs present. AE of adults and juveniles with pair of epimeral tubes on AE (Fig. 70). Juveniles. Deutonymph, protonymph and larva known. Deutonymph with GP and AP either fused (Bartsch 1977 b: fig. 365) or separated (Abé 2011: fig. 1 H). Area representing GP with two pairs of small internal gac, two pairs of pgs but zero sgs. GP and AP of protonymph fused; protonymphal GA with one pair of gac (Bartsch 1991 c: fig. 1 H); pgs and sgs lacking.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8EFF12A399FC57F884.taxon	discussion	Remarks. The presently eleven described species are psammobionts and live in warm-temperate and tropical sandy deposits. Records are from all oceans (Bartsch 2009 a; Abé 2011).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8FFF12A04AFE26FDE6.taxon	materials_examined	Type species. Scaptognathus tridens Trouessart, 1889. Adults. Adults with GA by fusion of GP and AP. Female GA often bi- or tripartite, with two or three transversely separated and differently ornamented parts. Posterior part of female GA with two to four pairs of pgs, genital sclerites with zero to two pairs of sgs. Two pairs of internal gac at and just beyond middle of length of GO (Abé 1990 b: fig. 1 E, 3 F, 2012: fig. 1 E). Ovipositor short. Number and shape of genital spines not known. Male GA uniform or bipartite. Posterior part of GA with 5 – 33 pairs of pgs lateral and posterior to GO (Newell 1984: fig. 795; Bartsch 1986 d: fig. 28, 1993 c: fig. 13 K). Two to three pairs of sgs on genital sclerites, two pairs of gac within genital cavity (Abé 1990 b: fig. 3 E; Bartsch 2003 d: fig. 16). Adults with pair of epimeral pores on AE. Juveniles. With deuto-, protonymph and larva. In deuto- and protonymph GP either separated or immediately adjacent to AP. GP uniformly sculptured or bipartite. Deutonymphal GP with two pairs of internal gac, two pairs of pgs and zero to one pair of sgs (Bartsch 1973 a: fig. 82, 1977 b: figs 340, 356). Protonymphal GP with single pair of gac and zero to one pair of setae (Bartsch 1977 b: fig. 355; Abé 1990 b: fig. 4 F, 2012: fig. 1 H). These setae small and close to primordial genital slit. All juveniles with pair of epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF7FF8FFF12A04AFE26FDE6.taxon	discussion	Remarks. The genus, with 31 described species, has been found in all oceans, in tropical and temperate zones (Bartsch 2009 a; Abé 2012).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF6FF8FFF12A5ABFB4BFAD5.taxon	materials_examined	Type species. Pachygnathus minutus Hodge, 1863. Adults. In both female and male GP and AP fused. Female GA with four to five pairs of pgs (rarely and unilaterally with three, exceptionally two pgs), subgenital setae lacking. Three small internal acetabula-like structures on either side of GO, situated in margin of large sacculus (Fig. 71). Ovipositor short, not extending beyond GO. Apical genital spines slender, spiniform, not sclerotized; number and arrangement not known. GO of male smaller than that of female; GA with about 10 – 25 pairs of pgs; of these zero to three pairs outlying, the others arranged in a ring around GO. In some species pgs setiform and smooth in others delicately plumose (Bartsch 1994 b: fig 58). Genital sclerites with three pairs of short sgs. Epimeral pores within epimeral vesicles. Juveniles. With deuto-, protonymph and larva, all stages with epimeral vesicles. In both deuto- and protonymph GP and AP separated. Deutonymphal GP with one (Figs 73, 74; Bartsch 1977 b: fig 380) or two pairs of pgs (Bartsch 1977 b: fig 386); the latter close together in posterior part of GP. Deutonymphs without sgs. Genital acetabula small, two pairs present, these distinct or very small (Figs 73, 74). Protonymphal GP with zero to one pair of pgs (Figs 72, 75; Bartsch 1977 b: fig. 388) but no sgs. Single pair of gac small.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF6FF8FFF12A5ABFB4BFAD5.taxon	discussion	Remarks. Forty-four species are described (Bartsch 2009 a, 2009 c). Many of them live in sandy deposits, in beaches or sand-filled pockets amongst a macroflora and fauna. The genus is spread world-wide but more species are known from the tropical and warm-temperate south than from the north (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF6FF8FFF12A2B9FC70F830.taxon	materials_examined	Type species. Soldanellonyx chappuisi Walter, 1917. Adults. In female GP and AP separated, in male both plates fused. Genital acetabula external, four to eleven pairs situated in posterior part of GP, lateral to GO. Females with three to seven pairs of pgs, each genital sclerite with zero to five sgs (Bartsch 1975 d: figs 2, 22). Ovipositor at rest short, when everted basally one pair of short genital spines, apically two pairs of short, smooth anterior and two pairs of short, slightly bifid posterior spines visible (Bartsch 1975 d: figs 16, 19). Males with about (10 –) 50 – 65 slender pgs and three pairs of sgs (Bartsch 2012: fig. 3). AE in a few species (S. monardi group) with epimeral pores in others (S. chappuisi group) without. Juveniles. With deutonymph, protonymph and larva. In both nymphs GP and AP separated (Bartsch 1975 d: figs 17, 18, 2011 a: figs 6, 7). Deutonymphal GP with two to five pairs of external gac, two pairs of pgs and zero to two pairs of sgs. Protonymph with one to two pairs of external gac; pgs and sgs not developed. Larvae and protonymphs with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF6FF8FFF12A2B9FC70F830.taxon	discussion	Remarks. Soldanellonyx is a freshwater genus. Nine species are known (Bartsch 2012), several of them are cosmopolitans. Most of the species are only known by their females.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A787FB6FFE75.taxon	materials_examined	Type species. Spongihalacarus longiscutus Otto, 2000.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A787FB6FFE75.taxon	description	Female. GP and AP fused to GA, this plate with four to five pairs of short, smooth pgs; genital sclerites with two pairs of sgs (Otto 2000 d: fig. 2). Acetabula not mentioned in the description. Length of ovipositor and number and shape of genital spines not known. AE with pair of epimeral pores. Male and juveniles. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A787FB6FFE75.taxon	discussion	Remarks. The single species described was found on the Great Barrrier Reef (Queensland, Australia); associated with a sponge that harbours red algae (Otto 2000 d). Unknown is the colour of the gut content, this might have given information on the diet of the mite, if it consists in algal cells or sponge tissue.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A559FEF8FB60.taxon	materials_examined	Type species. Stygohalacarus scupiensis Viets, 1934.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A559FEF8FB60.taxon	description	Male. Genital plate separated from anal plate. Male GO rather large (length slightly less than half length of GP). Five pairs of external acetabula on genital plate posterolateral to genital opening (Viets 1934 b: fig. 5). AE with pair of epimeral pores. Female. Not known. Juveniles. In nymphal stage (deutonymph) genital and anal plate separated. Genital plate with three pairs of external gac, two pairs of slender pgs and two pairs of sgs. AE with pair of epimeral pores. Protonymph and larva not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A559FEF8FB60.taxon	discussion	Remarks. A single species has been described (Viets 1934 a, 1934 b), extracted from a well in Macedonia. It is similar to species of the Soldanellonyx monardi group, though is easily distinguished from these due to the remarkably wide and coarsely bipectinate setae on the genua and tibiae. The presence of epimeral pores in adults is a character shared with S. monardi. Himejacarus, with a single species, H. morimotoi, seems to be similar to Stygohalacarus. Aside characters common in species of the genera Limnohalacarus and Soldanellonyx, Stygohalacarus and Himejacarus also share the presence of very wide and coarsely bipectinate setae on the genua and tibiae and the presence of epimeral pores. The two species are known by their males. Studies on more material of both species may prove them to be congeners.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A226FEA9F886.taxon	materials_examined	Type species. Thalassacarus commatops Newell, 1949. Adults. In female and male GP and AP fused. Female GA with three pairs of slender pgs; sgs lacking. Female with three pairs of internal gac arranged in line and extending anteriad slightly beyond middle of GO (Newell 1949: fig. 4). Length of ovipositor and number and size of genital spines not described. Male GA with about 25 pairs of slender pgs and four pairs of sgs (Newell 1949: fig. 3). Male GO smaller and distance to anal cone larger than in female. GO with three pairs of internal gac. No epimeral pores mentioned in the description. Juveniles. Only one nymphal stage seen, supposedly the deutonymph. GP separated from AP; GP with two pairs of internal gac and two pairs of pgs; sgs not mentioned in the description but obviously present (Newell 1949: fig. 10). Further juvenile stages and larva unknown.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF5FF8CFF12A226FEA9F886.taxon	discussion	Remarks. The single species at present found is spread along the Pacific coast of the United States of America (Newell 1949).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A787FC0DFB45.taxon	materials_examined	Type species. Acarus basteri Johnston, 1836. Adults. In both female and male GP and AP fused. Female GA with three to five pairs of pgs, genital sclerites with three to five pairs of sgs. Two to three pairs of gac often large and arranged in line (Figs 76, 81, 82; Thomae 1926: fig. 26; Bartsch 1976 c: fig. 26, 1998 b: fig. 122; Makarova 1978: fig. 6 GO female). Acetabula either almost equal-distanced or posterior pair slightly separated and enlarged. Ovipositor at rest extending beyond GO. Ovipositor with pair of basal and five pairs of apical genital spines; the latter in 2 + 3 arrangement, i. e. two anterior and three posterior pairs (Figs 77, 78). Genital spines spiniform, in T. basteri two anterior pairs of spines with delicate marginal denticles. Male GA with 40 – 160 slender pgs arranged scatteredly around GO. Male GO similar or slightly smaller than female GO. Genital sclerites with four to eight (nine) pairs of sgs, posterior pairs of sgs spiniform (Figs 79, 80). GO with two to three pairs of gac, these somewhat smaller than in female (Figs 79, 83). Acetabula in posterior part of GO, often immediately adjacent and with an opening to the exterior (Fig. 79; Makarova 1978: fig. 6, GO male; Bartsch 1996 b: fig. 31). AE of adults without epimeral pores. Juveniles. With a larval and one to two nymphal stages, in the former case only protonymphal stage present. GP and AP separated in both proto- and deutonymph. Deutonymphal GP with two pairs of pgs, two pairs of sgs and two pairs of internal gac (Bartsch 1976 c: fig. 40). Protonymphal GP with single pair of internal gac; neither pgs nor sgs present. Protonymph with small, larva with distinct, tube-like epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A787FC0DFB45.taxon	discussion	Remarks. One of the ten female T. basteri studied has two pairs of basal but a single antero-apical pair of genital spines instead of vice versa. A similar arrangement is present in T. affinis (Makkaveeva 1966: fig. ovipositor, female) The deutonymphal stage is suppressed in T. dissimilis (Bartsch, 1979 b), assumedly also in T. hexacantha (Viets, 1927) and T. longipes (Trouessart, 1888). Of T. dissimilis both a female and a male were dissected from protonymphal skins (Bartsch 1979 b: p. 28), in T. hexacantha populations from the White Sea, larvae, protonymphs and adults were present, but no deutonymphs (Nikitina 2013), and in respect to T. longipes the protonymphal stage was commonly taken (Newell 1947: p. 128), but obviously no deutonymphal. In these three species both females and males bear two instead of three pairs of gac. The genus Thalassarachna is spread in the northern Pacific, Atlantic, and adjacent areas (Mediterranean, Black Sea, Baltic, Arctic Ocean); 14 species are described (Bartsch 2009 a).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A209FDEAF9C8.taxon	materials_examined	Type species. Thalassophthirius auster Bartsch, 1988.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A209FDEAF9C8.taxon	description	Male. Male with GA by fusion of GP and AP. GO in ventral position, with 74 slender pgs arranged around GO and five to six sgs on each genital sclerite (Bartsch 1988 c: fig. 1 C). Number and arrangement of gac not known. Adults without epimeral pores. Female and juveniles. Not known. Number of nymphal stages not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A209FDEAF9C8.taxon	discussion	Remarks. A single specimen was extracted from a subtidal sample taken in the southern Atlantic Ocean, off South America (Bartsch 1988 c).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A1BEFD55F85F.taxon	materials_examined	Type species. Troglohalacarus dentipes Viets, 1937.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A1BEFD55F85F.taxon	description	Female. GP and AP fused. GA with three pairs of gac, anterior pair internal (?), two posterior pairs external (?) (Viets 1937: fig. 10). Male and juveniles. Not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFF4FF8DFF12A1BEFD55F85F.taxon	discussion	Remarks. Described on the basis of a single damaged female from freshwater, collected in a cave, northwestern Spain (Viets 1937). The species is expected to belong to the genus Halacarellus (Bartsch 1989 a) and is not treated in the course of further evaluations.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCBFFB3FF12A132FC54FF7E.taxon	materials_examined	Type species. Tropihalacarus spio Otto & Bartsch, 1999. Adults. Genital and anal plate fused in both female and male. Female GA with three pairs of slender pgs; no sgs on genital sclerites (Otto & Bartsch 1999: fig. 2). Ovipositor elongate, number and shape of genital spines not known. Male with 31 – 100 slender pgs, scatteredly arranged around GO, genital sclerites with five pairs of short sgs, two anterior pairs seta-like, three posterior ones slightly spur-like (Otto & Bartsch 1999: fig. 3). Length of male GO slightly less and distance to anal sclerites somewhat longer than in female. Three pairs of short internal gac arranged adjacent in posterior half of GO (Fig. 84). AE without epimeral pores. Juveniles. Deutonymphal GP separated from AP. GP with two pairs of small internal gac; two pairs of pgs but no sgs (Otto & Bartsch 1999: fig. 13). Protonymph and larva not seen.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCBFFB3FF12A132FC54FF7E.taxon	discussion	Remarks. Two species have been attributed to this genus, both are recorded from the tropical Pacific Ocean (Bartsch 1995 b; Otto & Bartsch 1999). In dorsal aspect the species are indeed similar with their ornamentation of the plates, elongate OC, long slender gnathosoma, but there are doubts that they belong to the same genus. More specimens of both adults and juveniles are necessary for further studies.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A653FD2EFC95.taxon	materials_examined	Type species: Halacarus parvirostris Trouessart, 1889. Adults. Female and male with GA and both with single pair of internal gac. In female pair of gac in about middle of GO (Newell 1984: fig. 573). GA with three pairs of slender pgs, genital sclerites with a pair of sgs. Ovipositor at rest hardly extending beyond GO; when everted apical 11 bi- or trifid genital spines seen (Bartsch 2008 b: fig. 7). In male gac in posterior part of GO (Bartsch 1996 d: fig. 7). GA with about 30 – 40 slender pgs arranged in a dense ring around GO, genital sclerites with four to five pairs of sgs; anterior pairs setiform, posterior pairs either seti- or spiniform. AE with pair of large epimeral pores. Juveniles. A larval and a single nymphal stage present. In protonymph GP separated from AP. GP without setae but with a pair of internal gac. Larva as in nymphs and adults with epimeral pores.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A653FD2EFC95.taxon	discussion	Remarks. The genus is spread in tidal as well as in deep sea basins but seems to be restricted to southern seas. Ten species have been described (Bartsch 2008 b).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A479FE7FFAA8.taxon	materials_examined	Type species. Werthelloides bathyalis Bartsch, 1986. Adults. Genital and anal plate fused. Female with eight to ten pairs of slender pgs, zero to one sgs and three pairs of rather large internal gac (Fig. 85), the latter in posterior two-third of GO. Ovipositor at rest short, shape and number of genital spines not known. Male genital plate much larger than that of female; small GO surrounded by approximately 90 slender pgs, genital sclerites with four to five pairs of spur-like sgs (Bartsch 1986 e: fig. 38). Epimeral pores lacking. Juveniles. A single nymphal stage (deutonymph) seen. Genital and anal plate separated. GP with three pairs of pgs, a pair of sgs and two pairs of large internal gac (Bartsch 1986 e: fig. 45). Protonymph and larva not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A479FE7FFAA8.taxon	discussion	Remarks. The single species was collected off the Island Réunion, western Indian Ocean, in 1050 – 1240 m depth (Bartsch 1986 e).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A29EFE4CF886.taxon	materials_examined	Type species. Winlundia filistoma Newell, 1984. Adults. In female and male GP and AP fused. Female GA with three pairs of pgs, genital sclerites with two pairs of sgs (Newell 1984: fig. 526). Ovipositor at rest slightly extending beyond GO. Number and shape of internal gac and genital spines not known. Male GA with 10 – 20 pairs of slender pgs, genital sclerites with three to five pairs of small sgs (Newell 1984: figs 540, 545). Epimeral pores not mentioned in the descriptions. Juveniles. Deutonymph with GP and AP separated. GP with two pairs of pgs, two pairs of minute sgs and two pairs of internal gac (Newell 1984: figs 536, 537). Any other nymphal stage and larva not known.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB3FF12A29EFE4CF886.taxon	discussion	Remarks. Two species are described, both are from South America, extracted from shallow water sandy deposits (Newell 1984).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFCAFFB0FF12A04BFB31FED8.taxon	materials_examined	Type species. Xenohalacarus longirostris Otto, 2000. Adults. Genital and anal plate fused. In both female and male GO rather small and in ventral position. Female GA with four to five pairs of pgs; sgs lacking (Otto 2000 e: fig. 4). Genital sclerites of male with five pairs of setiform sgs, GA with 28 pairs of pgs and at least two pairs of internal gac (Otto 2000 e: figs 2, 7). AE with epimeral pores. Juveniles. Only deutonymphal stage known. Its genital plate separated from anal plate. GP with two pairs of internal gac, two pairs of pgs but no sgs (Otto 2000 e: fig. 13). Protonymph and larva not seen. Remarks. A single record from sublittoral sandy deposits off eastern Australia (Otto 2000 e).	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFC7FFBEFF12A68BFE62FBD1.taxon	discussion	Remarks. The subfamily includes the freshwater genera Hamohalacarus, Himejacarus, Limnohalacarus, Soldanellonyx, and Stygohalacarus but excludes Parasoldanellonyx. In this genus the solenidion on tarsus II is in a dorsomedial position.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
03C887E5FFC6FFBFFF12A51FFB44FB19.taxon	discussion	Remarks. The subfamily Mictognathinae was erected by Otto (1999 c) to accommodate the two genera Mictognathus and Corallihalacarus. The characters presented in the diagnosis are correlated with the life-style. The four species known live in coarse sediment. The ' overlapping' of the dorsal plates is assumedly due to compression of a three-dimensional individual. Large, contiguous or fused dorsal and ventral plates, a fusion of the anterior epimeral and anterior dorsal plate, elaborate articular lamellae on the telofemora, genua and tibiae, are character states found in psammophilous species of the Copidognathinae and ' Halacarinae'. Moreover, the size of the dorsal plates and the length relation of the palpal segments are highly variable. A single seta on P- 4 is found both within the Copidognathinae and ' Halacarinae', and the majority of halacarids have laterally attached palps. The subfamily Mictognathinae may be justified but a more solid diagnosis is needed. The solenidion on tarsus II is in a dorsomedial position, tarsus III bears three dorsal setae and the nymphal stage, with its two pairs of gac, a single (?) pair of pgs (cf. presentation of the genus Mictognathus). In these characters the two genera Mictognathus and Corallihalacarus conform with the Halixodinae.	en	Bartsch, Ilse (2015): The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification. Zootaxa 3919 (2): 201-259, DOI: 10.11646/zootaxa.3919.2.1
