126 U.S. NATIONAL MUSEUM BULLETIN 236 



Leg 2 (fig. 446) with strongly developed endopodite; apex of exopo- 

 dite reaches halfway along 2nd endopodal segment. Transversal 

 row of spinules on 1st endopodite and exopodal segments. Spines 

 along external margin of 3rd exopodal segment notably small. 



Leg 3 (fig. 44c) with normally developed endopodite. 2nd endop- 

 odal segment with particularly strong, serrate internal seta; 3rd 

 endopodal segment with very strong, serrated apical spine and 3 in- 

 ternal setae. Longitudinal row of spinules on 1st exopodal segment. 



Leg 4 (fig. 43c) with short endopodite, reaching jointing between 2nd 

 and 3rd exopodal segments. Internal setae on 2nd and 3rd exopodal 

 segments strong and nude. Transversal row of spinules occurs on 1st 

 endopodal and exopodal segments. 



Baso-endopodite of leg 5 vestigial, scarcely visible; external process 

 with long seta. Exopodite cordate, with longitudinal carina, termi- 

 nating apically in spinule. External margin set with acute spinules, 

 interrupted about halfway along that margin by short seta. Addi- 

 tional small seta at extreme apex of exopodite (fig. 43d). 



Adult male, total length 0.48 mm.; gTeatest diameter 0.33 mm. 



The adult male differs from the adult female in the following points : 



1. Body little less slender, very broadly ovate, nearly circular. 

 Rostrum scarcely developed and much smaller than in female, no more 

 than fraction of base visible in dorsal aspect (fig. 41). 4th thoracic 

 somite, as 2nd and 3rd, with well-developed epimeral plates, 5th 

 thoracic somite small. Genital complex with slightly convex lateral 

 walls, hollowed caudally, only slightly backwardly produced and cover- 

 ing fraction of furcal rami, 2 fine haus on each side (fig. 44d). Anal 

 somite fitted into hollowed part of genital complex, scarcely visible 

 from above, anal plate very distinct, slightly larger than in female. 

 Furcal rami shorter, curved under body, about 1% times as long as 

 wide, greatest diameter at half their length, internal margin straight, 

 external margin strongly swollen. 5 marginal setae and an appendicular 

 seta on each ramus. 5th legs very broad, fitting into space between 

 epimeral plates of 4th thoracic somite and genital complex (fig. 43/). 



2. Malleated pattern in male even more strongly developed than in 

 female. Cephalic somite, as in female, has internal system of strongly 

 chitinized trabeculae, here distinctly visible through carapace. Some 

 scattered hairs along edge of body and seta on epimeral plate of 3rd 

 thoracic somite. 



3. Antennules 4-segmented: 1st segment without setae but with 

 row of very acute spinules; 3rd segment slightly swollen proximally, 

 with short spiniform process and distally with slightly protruding 

 conical process, carrying aesthetasc and 2 setae. Setation of anten- 

 nule represented in figure 42h. 



