202 Bulletin, Vanderhilt Marine Museum, Vol. II 



rounded and well separated from one another. The male belt is nar- 

 rowly triangular, five-segmented ; the third, fourth and fifth segments 

 being fully coalesced into onej the terminal segment is narrowed, 

 triangulate. 



The antennulae have the basal joints much enlarged, flattish; the 

 second and third joints elongated, cylindrical. 



The basal joint of the antennae is enlarged; the free articles are 

 slender, tapering. 



The eyestalks are small, tapering, movable. The cornea is terminal. 



The chelipeds are distinctly unequal in the female and more pro- 

 nouncedly so in the male. The merus is short, three-sided ; the carpus 

 is nearly square in outline, slightly convex on the upper surface, the 

 inner lateral angle is weakly dentate in the female, less so in the male ; 

 the propodus is arched, the palm high, the fingers slightly longer than 

 the palm, tapering, finely dentate, tips curved. In the female the 

 large cheliped has the propodus nearly a third thicker than does the 

 smaller one. The male has the large propodus nearly twice as high 

 as the small one and much more inflated. Both lateral margins of 

 the merus and propodus are fringed with long setae. 



The ambulatories are long, slender; the third pair is the longest; 

 the second pair almost as long as the third ; the first pair are next in 

 length, being scarcely three-fourths as long as the second pair; the 

 fourth pair of legs are only a trifle shorter than the first pair and have 

 the dactyli recurvate. All four legs have the meral joints about one- 

 third wider than the related carpus. Both anterior and posterior 

 lateral margins of all the legs are fringed with setae. 



The external maxillipeds are set wide apart, the space between them 

 being equal or slightly greater in width than one maxilliped. The 

 ischium is subtriangular, with a single prominent longitudinal groove 

 on its outer face; the merus is not quite as long nor as wide as the 

 ischium and is subovate, set obliquely on the ischium; the palp is 

 large, three-jointed, cylindrical; the inner lateral margins of the 

 ischium and merus are fringed with setae as is also the distal joint 

 of the palp. 



Synonymy. — Chasmocarcinus latipes Rathbun, Proc. U. S. Nat. Mus., 

 vol. 21, p. 602, pi. 43, fig. 5, 1898 ; Bull. 97, U. S. Nat. Mus., p. 57, 

 text figs. 25 and 26, 1918. 



