.312 Carciiwlogical Fauna of Indt'ri. 



oB the carapace ; its free edge is turued vertically downwards and 

 rather deeply grooved from side to side. 



Tlie aufcero-lateral borders are not much more than half the length 

 of the postero-lateral : they are thin and sharp, and are cut into three 

 teeth, of which the first is broad and bicuspid and the other two are 

 acute. On the postero-lateral borders, just behind the junction with 

 the antero -lateral, is a denticle. 



The eyes ai'e small but well-formed, and are freely movable. The 

 orbits conceal the retracted eyes to doi'sal view: their upper margin is 

 fissured near the middle, and the lower margin is slightly excavated 

 just below the outer angle: the inner angle of the lower margin is not 

 prominent, though dentiform. 



The chelipeds in both sexes are very unequal, the larger one being 

 not quite twice as long as the carapace ; their surface, under the lens, 

 is finely frosted : tlie inner angle of the wrist is strongly pronounced 

 and is capped by a pair of acute teeth. 



Legs moderately stout, unarmed, smooth, almost hairless : the 

 third pair, which are somewhat the longest, are about two-and-a-half- 

 times the length of the caiapace. The dactyli are compressed-styliform. 



Colours in spirit french-grey, fingers much darker grey. 



A single female specimen, from off the Travancore coast 430 fms., 

 has the carapace 13 milh'm. long and 16 millim. broad. 



This species is closely related to Pilunmoplax heterocMr (Studer) 

 Miers, but is distinguished from it by the entire and more prominent 

 front, by the absence of transverse markings on the carapace, by the 

 longer legs, and by the smoothness of the chelipeds and legs. 



From Pihimnoplax abyssicola Miers, which it also closely resemble.^!, 

 it is distinguished by the smooth caiapace (to tlie naked eye), by the 

 turned-down milled edge of the front, by the spinule on the postero- 

 lateral border, by the fissured upper-margin of the orbit, and by the 

 double spine at the inner angle of the wrist. 



Distribution : Off Atlantic coasts of North America (Florida and 

 Georgia) 440 and 70 to about 200 fms. Off Travancore coast 430 fms. 



A single specimen from the latter locality is in the Indian Museum 

 collection. 



[Platypilumnus, Wood-Mason, 



PlaUjpilwnnuf:, Wood- Mason MS., Alcock, Ann. Maf;. Nafc, Hist., May, 1894, 

 p. 401 : Joarn, Asiatic Soc. Beng.il, Yol. LXVII. pt. 2, 1898, p. 232: Investigator 

 Deep Sea Brachyura, p. 62. 



This efenus, like so many of the preceding, has strong affinities with 

 654 



