214 Bulletin Vanderbilt Marine Museum, Vol. VII 



region, almost on the posterior margin. In line with these, there 

 is also a strong, posteriorly directed, median spine on the poste- 

 rior margin of the first abdominal somite of both males and 

 females. There are three primary spines on the branchial region 

 in series, the anterior one being sometimes equally strong, some- 

 times very much weaker than the posterior two of this series. 

 There are also several small spinules on the protogastric, hepatic, 

 epibranchial and mesobranchial regions, these forming a near- 

 marginal series on the hepatic and branchial regions. While the 

 distribution of these spines is similar on all eight specimens, 

 their number and degree of development is quite variable, the 

 spines attaining greatest development on the large old males, 

 while on the one female the lesser spines are reduced in some 

 degree, some being entirely absent. 



The male belt is of the usual narrowed triangulate shape, the 

 proximal article is dorsolateral with a strong, deflected, median 

 spine, directed posteriorly; the second somite is short, lateral, 

 with a small median tubercle ; the third somite is hinge-like with 

 the lateral angles produced in strong, triangulate processes, each 

 abutting the coxal joint of the fifth pair of legs ; the fourth article 

 is ventrad, about as long as the third but narrower with the pos- 

 terior median area elevated; the fifth somite is 1.5 times as long 

 as the fourth with the postmedian area tumid; the sixth and 

 seventh somites are fused ; lateral nodes on either margin indicate 

 the suture; the sixth somite is 1.3 times as long as the fifth 

 somite, the fused seventh somite is 0.8 as long as the sixth ; the 

 sixth somite has a prominent median dilation ; the seventh somite 

 is triangulate, rounded distally. 



The female belt has the first article dorsolateral, bearing a 

 strong spine, directed posteriorly, as in the male, but the second, 

 third and fourth articles are short, wide, hinge-like, with the 

 median area set apart from the lateral by paired longitudinal 

 constrictions ; the fifth, sixth and seventh somites are completely 

 coalesced, forming a wide, subcircular, externally convex, in- 

 ternally concave pouch, which extends to the basal articles of the 

 legs. 



The male chelipeds are much longer in ratio to the related 

 body than are those of the female. The merus and carpus are of 

 similar contour and similarly spinose in the two sexes, but the 

 male propodus has the palm greatly dilated, the outer face being 



