The genital area of Halacaridae (Acari), life stages and development of morphological characters and implication on the classification Author Bartsch, Ilse text Zootaxa 2015 3919 2 201 259 journal article 10.11646/zootaxa.3919.2.1 8a0f71e3-5416-41c5-8e7d-b4cc574b7340 1175-5326 245246 8CB77F9E-A35E-43E2-91F7-7822AE421B33 Bathyhalacarus Sokolov & Jankovskaja, 1968 (Fig. 27) 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 1989b : 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 1989b: 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 1982a : figs 28, 41). Protonymphal GP with single pair of gac ( Bartsch 2005a: fig. 16 ); neither pgs nor sgs present. AE of larva with epimeral pores ( Bartsch 2005a: fig. 17 ). 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 2009a ).