184 Bulletin, Vanderbilt Marine Museum, Vol. II 



teeth is deeper than those between the other teeth and is unequally 

 proportioned, the inner side being the longer and more arcuate, the 

 outer side is abrupt, relatively straight. The outer pair of teeth are 

 wider and a trifle longer than the submedian teeth, and the preorbital 

 teeth are acute, not quite as long as the median pair ; just behind the 

 preorbital tooth and separated from it by a shallow sinus ; there is on 

 the superior orbital margin a second obtuse tooth ; there are two open, 

 V-shaped sinuses on the superior orbital margin ; the postorbital tooth 

 is small, acute; the inferior orbital margin has one wide sinus below 

 the postorbital angle; the lower margin is sinuate and beaded; the 

 inferior inner orbital tooth is broad, triangulate and more prominent 

 than any of the teeth of the frontal margin. There are eight small, 

 triangulate, acuminate teeth on the lateral margin ; of these the second, 

 fourth, sixth and eighth are a trifle smaller than the alternate teeth. 

 The postlateral margin is sinuate; the posterior margin is about as 

 wide as the space between the postorbital angles and is relatively 

 straight. The male abdominal belt is composed of five articles, the 

 first and second segments being wide and transversely keeled, the 

 third, fourth and fifth segments being completely fused; the sixth 

 segment narrows distally, the seventh segment is small, triangulate. 

 The sternal plastron is broad, the segments sharply defined. 



The antennulae have the basal article greatly enlarged, the free 

 articles very slender, folding obliquely. 



The antennae have the basal article extending so that its inner dis- 

 tal margin of the article is produced in two node-like processes; the 

 free second and third articles are small, the flagellum is very slender, 

 about one and one-half times the length of the orbit. 



The external maxillipeds have the merus rounded, somewhat flaring 

 on its outer distal border. 



The chelipeds of the male are exceedingly long and slender, more 

 so than those of the female. The male chelipeds have the merus as long 

 as the carapace between the base of the lateral spines ; it is three-sided, 

 with the anterior lateral margin armed with four weak and widely 

 spaced, obliquely outward pointing spines, and the posterior distal 

 angle is armed with one outpointing spine ; the upper surface is rough 

 with granules, frequently set in the form of arcuate, transverse rugae ; 

 the carpus is not quite one-third as long as the merus and is armed 

 with a very small, subdistal spine on its lower lateral margin, and 

 has the inner distal angle produced into an extremely long, carinate 

 spine which has its acute tip reaching to one-third the length of the 



