46 Bulletin, Vanderbilt Marine Museum, Vol. II 



going forward to behind the orbital cavity where it unites with a 

 transverse groove which extends across the frontal region. There is 

 also a deep groove extending outward and forward across the bran- 

 chial region from near the urogastric groove. The gastric and hepatic 

 regions are moderately convex, the intestinal region bears a rosette- 

 like arrangement of five radiating rugae ; the branchial region is mod- 

 erately convex. The first, second, third and fourth abdominal seg- 

 ments of the male are dorsally visible, narrow, densely setiferous ; the 

 other three are entirely ventral, the last segment being triangulate 

 with the tip rounded. The sternal plastron is wide, flattish densely 

 setiferous. The pterygostomian region is setose, concave a little in 

 advance of the breathing aperture which is densely fringed by regu- 

 lar, stiff setae. 



The external maxillipeds narrow distally; the exognath is rod-like, 

 extending to midway the lateral margin of the merus ; the ischium is 

 much wider and slightly longer than the merus and is produced to a 

 distinct rounded lobe at its inner distal angle ; the merus is almost as 

 long as the ischium but is much narrower and narrowed distally with 

 its inner lateral face channelled and sinuate for the reception of the 

 palp — ^the long, cylindrical second joint of which fits between the 

 laminate projection of the outer distal and inner lateral margins ; the 

 distal article of the palp is small, conical. The entire outer face of the 

 maxilliped is densely setiferous. 



The antennulae have the second and third joints long, cylindrical, 

 folding obliquely. 



The antennae are small. 



The chelipeds are equal in the female but are decidedly unequal in 

 the male. The meral joint is arched, small, three-sided, with both 

 lower lateral margins fine dentate; the carpus is small, of irregular 

 shape, moderately convex, produced to a tooth at its inner distal 

 angle ; the propodus in the female is scarcely wider than the preceding 

 joints and is decidedly arched ; the palm is short, moderately convex, 

 three-fourths as high as long; the fitngers are deflected, about one- 

 third longer than the palm, tapering; the outer face of each finger 

 with two longitudinal ridges separated by grooves ; the cutting edges 

 regularly dentate, meeting; tips curved. In the males the chelipeds 

 are markedly unequal, the propodus on the right side having the palm 

 fully twice as much inflated as on the left, the height of the right 



