100 A. Alcock — Carcmological Fauna of India. [No. I, 



preocular tooth (parallel witli, but less prominent than, tbe front), 

 below which at the inner suborbital angle is an almost equally promi- 

 nent coarse spine : there are also two other teeth — one at the external 

 orbital angle, and the other between this and the preocular tooth — 

 hardly distinguishable from the ordina^fy spines of the carapace. The 

 eyestalks which are slender, tapering, and of good length, do not nearly 

 fill the shallow orbital cavity. 



The antennules fold longitudinally in fossae, beneath the front : 

 their basal joint is large. The antennae arise almost in the same trans- 

 verse line with the antennules : their basal joint forms a large part of 

 the floor of the orbit. 



The epistome is sunk below {i.e. is really arched much above) 

 the plane of the external maxillipeds. The efferent branchial channels 

 are defined by an incomplete ridge, and are patulous. The external 

 maxillipeds are slender, and leave the mandibles exposed between them : 

 the merus is obovate and narrower than the ischuim, the palp is 

 coarse. 



The chelipeds and legs are spiny and bristly, the spines in the case 

 of the legs being well pronounced only on the dorsal surface of the 

 meropodites. 



In the female the chelipeds are shorter and not much stouter than 

 the legs and are about as long as the carapace. 



The legs are little unequal in length, the first pair which are 

 slightly the longest being hardly half as long again as the carapace : 

 they all end in long, stout, cylindrical, sharply styliform dactyli. 



The abdomen of the female is seven-jointed and covered with 

 coarse hairs : the first two segments are broader, and on them the 

 spines decrease in size to the seventh segment which is smooth. 



The colour in life is recorded by Dr. A. R. Anderson as pale 

 bluish yellow. 



Length of carapace and rostrum 64 millim., breadth 55 5 millim., 

 depth 35 millim. 



A single female from off the west coast of Ceylon 180-217 fms., on 

 a foul bottom of broken coral. 



Trachycarcinus, Faxon. 



Trachycarcinus, Faxon, Bull. Mus. Comp. Zool. XXIV. 1893, p. 156, and Mem. 

 Mus. Comp. Zool. XVIII. 1895, p. 25 : Alcock, Investigator Deep Sea Brachynra, 

 p. 58. 



" Carapace pentagonal, moderately convex, lateral margins long, 

 nearly straight, toothed. Front narrow, produced, three-toothed. 

 Orbits large with forward aspect, imperfect, with two hiatuses above 



