(Fig. 34 and 35)
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.
Remarks. The three species described have been collected in the eastern North Atlantic Ocean (Bartsch 2009 a).