262 A. Alcock — Carcinological Fauna of India. [No. 2, 



Tlie carapace is broader than long, and its surface, like the whole 

 under surface of the body and the whole surface of the arms, is closely 

 covered with large flat-topped pearly granules, except in the deeply- 

 excavated hepatic areas where the granules are small and rather 

 distant. 



The regions are well demarcated by grooves, and (except the 

 hepatic regions, which are markedly excavated inside of the rather 

 prominent antero-lateral borders) are tumid. A broadish median 

 ridge extends from the front to near the middle of the cardiac region, 

 where it ends in a stout tubercle, and in continuation of the same line, 

 on the intestinal region, are two similar tubercles : there are also four 

 similar tubercles on the gastric region, — two on either side of the 

 median ridge. 



The front is broadly bidentate : behind it the pterygostomian 

 ridge, which ends at a coarse denticle, can be seen in front of the 

 antero-lateral margin in a dorsal view : the hepatic portion of the 

 antero-lateral margin is thickened and ends abruptly at a very promi- 

 nent granular swelling; behind this the lateral margin is most elegantly 

 curved. The posterior margin is rather prominent and is bilobed, the 

 apex of one of the intestinal tubercles being seen between the lobes in 

 a dorsal view. 



The chelipeds are rather more than half again as long as the 

 carapace : the arm is coarsely granular like the carapace, the wrist and 

 hand are granular under the lens : the hand has the outer edge some- 

 what thickened and raised and the inner side swollen : the fingers are 

 hooked, are twice the length of the hand, and open in a nearly vertical 

 plane ; their opposed edges are finely denticulate with larger denticles 

 at distant intervals and with a good many hairs. 



The abdomen of the male has a tooth at the penultimate segment. 



In the Indian Museum is a specimen from the Andamans and one 

 from the Orissa Coast. 



Arcania, Leach. 



Arcania and Iphis, Leach, Zool. Miscell. III. p. 19. 



Arcania and Iphis, Milne Edwards, Hist. Nat. Crust.tfl. 133, 138. 



Arcania and Iphis, Bell, Trans. Linn. Soc, Vol. XXL 1859, pp. 309, 311, 312. 



Arcania, A. Milne Edwards, Nouv. Archiv. du Mus. X. 1874, p. 48. 



Arcania, Miers, ' Challenger ' Brachyura, p. 299. 



Carapace globular, ovoid, or rhoraboidal, with the lateral and 

 posterior margins armed with definitelj^-situated large spines (except 

 in Arcania gracilipes Bell, in which large tubercles take the place of 

 spines, and A. orientalis Miers, in which spines are absent), and with 



