526 BULLETIN 54, UNITE!) STATES NATIONAL MUSEUM. 



pairs are present and are much larger than in rl;> </!/</< f><>rrei, all the 

 pairs except, perhaps, the third and fourth, overlapping across the 

 median line. The first pair are, as usual, of somewhat complex form. 

 Roughly quadrilateral in shape, the posterior corner is produced into 

 a hook-like process directed inward. A little behind the middle of 

 its length the lamella is crossed by a transverse fold, forming on its 

 outer or lower surface a deep groove, the anterior margin of which is 

 produced as an overlapping ridge. On the inner, or, in its natural 

 position, upper, face of the lamella the fold projects as a strong ridge 

 which for part of its length is fringed with digitate processes. The 

 front edge of the second pair of oostegites is received into the groove 

 on the lower surface of the first pair. The last two pairs are strongly 

 fringed with setae on the posterior edge. 



"Five pairs of biramous pleopods are present, successively dimin- 

 ishing in size posteriorly, those of the right side being, as already 

 mentioned, considerably larger than those of the left. In the first 

 pair the exopodite (lobe 5, according to the nomenclature of Giard and 

 Bonnier) is roughly quadrilateral in shape and much smaller than the 

 endopodite (lobe <?), which is long and pointed. In the posterior pairs 

 the exopodite approaches more-closely in size and shape to the endo- 

 podite. The last segment of the abdomen is very small, and bears 

 articulated to its posterior margin a pair of lanceolate lamellae, of 

 which the right is broader and slightly longer than the left. These 

 lamellae may possibly represent the sixth pair of pleopods, but a com- 

 parison with Giard and Bonnier's figure of the corresponding region 

 in Pals&gyge borrei suggests that we have here to do with the rudi- 

 mentary pleura! lamellae (lobe a of Giard and Bonnier), which, sepa- 

 rated by a distinct suture from the fifth and sixth segments in the 

 last-named species, are here only distinct on the sixth segment. If 

 this view be adopted the sixth pair of pleopods are entirely absent. 

 In all the pleopods the surface of the endopodite is roughened by irreg- 

 ularly transverse rugae, which are most distinct on the anterior pairs. 



"Male. A male individual about 3 mm. long was found under the 

 pleopods of the female. The body is symmetrical, lanceolate in out- 

 line, the fourth thoracic segment being the widest. A pair of eyes 

 are present near the posterior corners of the head. Both antennules 

 and antennae are well developed, the former having three, the latter 

 five segments. As in the female, no distinct rudiments of the first 

 maxillae could be identified. The second maxillae have the form of 

 rather large, rounded tubercles. The maxillipeds are present as long, 

 slender processes, each tipped by a single seta, inserted on each side 

 close to the base of the lower lip. The seven pairs of thoracic feet 

 are all similar and of the usual form, with powerful subchelate 

 terminations. 



These lamellae, attached to the sixth abdominal segment, are the uropoda. H. R. 



