Carcinohgical Fauna of India. 213 



Hyastenus calvarius, n. sp. 



This species — females alone being available for comparison — differs 

 from H. planasius chiefly in the following characters : — (1) there is an 

 erect claw-like spine on the posterior border of the carapace in the 

 middle line ; (2) the spines of the rostrum are straight, divergent, and 

 about half the length of the carapace ; (3) the dactyli are longer and 

 slenderer. 



Three females — two of which are laden with eggs — from the 

 Andamans. The larger egg-laden female measures 14 millim. from 

 the tip of the rostrum to the posterior border of the carapace. 



Description of the female. 



Carapace elongate-ovate, with the surface, when denuded of 

 scattered setse, smooth and polished : the gastric region is very convex : 

 the only armature of the carapace is ( 1) a large erect claw-like spine 

 near the posterior border in the middle line, (2) a small lateral epibran- 

 chial spinule on either side, and ( 3 ) two or three granules along the 

 antero-lateral border in the pterygostomian region. The rostrum is 

 formed of two straight divergent spines, the length of which is about 

 half that of the carapace proper. The antero-lateral angle of the pro- 

 minent supra-ocular eave is sharp ; and that of the basal antennal joint 

 is produced to form a spine which is plainly visible from above. 



The legs are more or less fringed with stout club-shaped hairs : 

 the second pair are, as usual, the longest : the dactyli are long and 

 slender, and are recurved, with the posterior margin serrate. The 

 chelipeds are slender, and the fingers meet in the greater part of their 

 extent. 



Hyastenus sebse, White. 



Seba, Thesaurus, III. xviii. 12. 



Hyastenus sebse, White, P. Z S., 1847, p. 57 ; and Ann. Mag. Nat. Hist., Vol. 

 XX. 1847, p. 61 ; and ' Samarang' Crustacea, p. 11. 



Hyastenus sebse, A. Milne-Edwards, Nouv. Archiv. du Mus., VIII. 1872, p. 249. 

 Hyastenus sebse, de Man, Archiv. fur Naturgesch., LIII. 1887, p. 223. 

 Hyastenus sebse, Miers, 'Challenger' Brachyura, p. 56. 

 Hyastenus sebse, Orfcmann, Zool. Forsch. Austral. Malay. Archip. Jena, 1894, p. 42. 



Carapace very elongate -triangular, its surface eroded and sculp- 

 tured, but without distinct tubercles or spines. The rostral spines, 

 which are equal in length to the carapace, are paralled in their proximal 

 half. The chelipeds in the male are equal in length to the carapace 

 plus one-third of the rostrum : their merus is not much stouter than 

 that of the next pair of legs, but the palm is broadened and somewhat 



inflated : the fingers, which are hardly more than half the length of 

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