1898.") A. Alcock — Carcinological Fauna of India. 109 



Chelipeds equal ; outer surface of wrist and hand finely granular 

 or rugose under the lens ; upper edge of arm crested but not foliaceously 

 expanded ; both upper and lower edge of hand crested. Fingers very 

 short and stumpy, pointed. 



Legs smooth : upper edge of merus carpus and propodite crested 

 and having a few scattered hairs ; also a few scattered hairs on the 

 surface and lower edge of propodites. 



Colours in spirit yellow, with diffused orange-red patches ; fingers 

 brown, white at tip. 



In the Indian Museum are three specimens from the Andamans. 



Alliance III. Euxanthoida. 



Euxanthus. Hypocoelus. 



Euxanthus, Dana. 



Euxanthus, Dana, Silliman'a Amer. Journ. Sci. and Art. (2) XII. 1851, p. 125 ; 

 Proo. Ac. Nat. Sci. Phila. 1852, p. 75 ; and U. S. Expl. Exp. Crust, pt. I. p. 173. 

 Melissa, Strahl, Archiv. far Naturges. XXVII. 1861, i. p. 101. 

 Euxanthus, A. Milne Edwards, Nouv. Archiv. du Mus. I. 1865, p. 289. 



Carapace very broad, strongly convex in both directions, with the 

 regions well delimited and subdivided into convex lobules. 



The antero- lateral borders are sharp and somewhat irregularly 

 scallopped, the lobes often subpyramidal or dentiform : they do not 

 terminate at the orbit, but are prolonged, beneath the orbit, to the 

 buccal cavern. The postero-lateral borders are very short and very 

 concave. 



The front is of no great breadth (about a fifth the greatest breadth 

 of the carapace), bilobed, and prominent. The supra-orbital border and 

 the inner angle of the lower border of the orbit are tumid, and the rest 

 of the orbital margin is very low and forms an unbroken curve, with 

 only one closed suture line. The eyes have short thick stalks. 



The antennules fold nearly transversely. The basal antennal joint 

 is prolonged right into the orbit, and the short flagellum is therefore 

 placed inside the orbit. The outer border of the merus of the external 

 maxillipeds is oblique. 



The chelipeds are equal in both sexes, and are relatively small and 

 light. The fingers are rather long-pointed, and have the tip slightly 

 but distinctly hollowed out. 



Abdomen of the male five-jointed, the 3rd-5th somites being fused. 



Crabs of medium size, easily recognized by the peculiar form of the 

 basal joint of the antenna? and the course of the antero-lateral margin 

 of the carapace. 



