58 



The epistome is arched much above the plane of the external maxillipeds. 

 The efferent branchial channels are defined each 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 ischium, 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 surfaces 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 styhform dactyU. 



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

 the first two segments are narrow and bear some spines in the middle line, the 

 other 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 (34 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. 



Teachycarcinus, Faxon. 



Trachycarcinus, Faxon, Ball. Mms. Comp. Zool. XXIV. 1893, p. 156 : Mem. Mas. Comp. Zool. XVIII. 1S95, p. 25. 



" Carapace pentagonal, moderately convex, lateral margins long, nearly 

 straio'ht, toothed. Front narrow, produced, three-toothed. Orbits large with 

 forward aspect, imperfect, with two hiatuses above, one below, and one at the 

 inner angle ; lower Avail formed chiefly by the carapace. Anterior margin of 

 buccal cavity not distinctly defined, epistome short, ridges of the endostome 

 developed. Sternum long and rather narrow. Abdomen of male narrow and five- 

 jointed, the third, fourth, and fifth segments consolidated. Eye-stalks very 

 small, retractile within the orbits. Antennules longitudinally folded. The 

 antennae lie in the inner hiatus of the orbit ; their basal segment is but slightly 

 enlarged, not filling the hiatus at the inner angle of the orbit nor attaining to 

 the front, subcylindrical, unarmed, imperfectly fused with the carapace ; the 

 second segment is longer and slenderer than the first, the third segment about 

 equal to the second in length, but slenderer ; all these segments are furnished 

 with long and coarse setaj ; the whole antenna is less than one half as long as the 

 carapace. The ischium of the outer maxillipeds is produced at its antero-inter- 

 nal angle ; the merus of the same appendages is rounded at the antero-external 



