9;^ 



II. HoillOeOSCeliS n. gen. 



FEMALE. The head small ami distinctly defined from the oiiciilai', rather 

 depressed trunk. Frontal and marginal borders and sub-median skeleton \\ell developed. 

 Antennula? of scarcely medium length, 2-jointed. Antenn* wanting. Mouth i-ather small, 

 the mouth-border being somewhat nairow, with well developed hairs. Maxillulte without 

 additional branch. Maxillae about middle-sized, smooth. Maxillipeds of medium size, second 

 and third joints coalescent. Body entirely naked in the adults, at the utmost a few hairs 

 on the sides behind the head; in the recently hatched and younger specimens the hair 

 covering resembles that of the male. The trunk-legs are situated on the lateral margins; 

 they are small, each apparently consisting of a rather tliick, short basal part which is jointed 

 without articulation to an elongated, very narrow conical, sometimes partly hairy branch, at the 

 base of which the basal part bears either a few setts or just a vestige of another branch. 

 Abdomen wanting. Well developed genital area with a transverse cliitinous arch, opening 

 towards the front and surrounding the genital apertures, wldch are situated close together, 

 and the entrances of receptacula seminis. Rather close behind the genital area are the two cau- 

 dal stylets wMch are a little thicker and longer than the legs. — Spermatophores frequently seen. 



MALE. Body seen from below elongated ovate, from nearly twice to a little more 

 than twice as long as broad. Length of the head somewhat exceeding a tlurd of the total 

 length. (The antennulse 2- or 3-jointed, and very small antennse are perhaps found in one 

 species). In other respects all the other organs of the head, as well as the trunk-legs and 

 caudal stylets, mostly agree with those of the female. The trunk, except the anterior part 

 of the ventral surface, is covered rather closely all over with comparatively short haii^s. 



OVISACS. Are deposed freely, and are of moderate or rather large size, containing 

 few, six to eighteen, eggs which are very or exceedingly large. The number of sacs laid 

 by one female can amount to eight. 



LARVA. Is known of both species. Antennae much longer than in any other 

 genus, more than twice the length of the antennulse, owing particularly to the fact that the 

 penultimate joint is very much elongated; the terminal seta is very long. Maxillulae I have 

 been unable to discover. Maxillae only 2-jointed, the second and third joints being fused 

 and forming one curved joint, which, moreover, along the larger part of both margins is 

 furnished with extremely fine and short, setiform processes. Maxillipeds far behind the 

 maxillte; all joints smooth; second joint half or scarcely half as long as the third one. 

 Peduncle of the natatoi-y legs rather slender. Third segment of the abdomen together with 

 the small caudal stylets distinctly articulated to the segment, much smaller than the second 

 segment. The longest seta of the caudal stylets sometimes shorter, sometimes considerably 

 longer than half of the cephalothorax. 



POST-LARVAL DEVELOPMENT. Observed only in one species and described 

 above, p. 55. 



