1900.] A. Alcock — Garcinologiral Fauna of India. 311 



Two specimens, from the Gulf of Martaban, 60 and 67 fms. 

 The carapace of the largest is 13 millim. long and 19 millim. broad. 

 Colours in glycerine, reddish : in the middle of the carapace is a 

 large deep-red shield with a milk-white edge and centre. 



This species closely connects Psoplieticus with Oarcinoplax. 



Pilumnoplax, Stimpson restr. 



Pilumnoplax, Stimpson, Proc. Ac Nat. Sci. Philad. 1858 (1859) p. 93: Miers, 

 Challenger Brachynr.i, p. 225 : Alcock, Investigator Deep Sea Brachynra, p. 74. 



Carapace depressed, flat, a little broader than long, the regions 

 very faintly indicated. Fronro-orbital border two-thirds, or more, the 

 greatest breadth of the carapace : the antero- lateral borders, which are 

 toothed, are slightly arched or oblique. Front sqnare-cut, straight, 

 rather prominent, more or less confluent with the supra-orbital angles, 

 often notched or grooved in the middle line. 



Supra-orbital border often with two fissures. The antennal flagel- 

 lum, which is of good length, stands in the orbital hiatus. The 

 antennules fold transversely, or nearly so. 



Mouth and mouth-parts as in E iterate. 



Chelipeds either subequal or unequal, much more massive than the 

 legs. Legs slender, their dactyli compressed. 



The abdomen in both sexes is seven-joiuted : in the male the 3rd 

 segment covers the whole width of the sternum between the last pair 

 of legs. 



Distribution: Tropical and S. Atlantic (deep sea), Arabian Sea 

 (deep), Japan, Fiji. 



The species of Pilumnoplax are characterized by the flat, depressed 

 carapace, which is also comparatively narrow and, owing to the 

 prominence of the perfectly straight front, is subhexagonal in shape. 



13. Pilumnoplax americana, Rathbun. 



Tilumnoplax americanus, Mnry J. Rathbun, Bull. Lab. Nat. Hist. Iowa, 1898, 

 p. 283, pi. vii figs. 1, 2. 



Pilumnoplax Sinclairi, Alcock, Investigator Deep Sea Brachyura, p. 74, pi. iii. 

 fig.l. 



Carapace subquadrilateral, much depressed, a little more than 

 three-quarters as broad as long, very finely frosted, perfectly bare, the 

 regions fairly indicated. 



Front horizontal, slightly prominent, square cut, grooved but not 

 distinctly notched in the middle, more than a third the greatest breadth 

 J. ii. 41 



