208 



A. Alcock — Carcinologicul Fauna of India. 



[No. 2, 



II. Denuded 

 carap ace 

 smooth and 

 polished, <{ 

 with a few 

 large 

 spines. 



f 1. Carapace f\. 

 triangular, I 

 with a large 

 e pi branchial [ 

 spine and at-} 

 least one large I 

 sub-hep a t i c ii. 

 tub ercle on [ 

 either side. [_ 



2. Carapace fi. 

 elongate, 

 with a small 

 e p i b ranchial 

 tubercle, and<j ii. 

 with none of f 

 the sub-hepa- 

 tic tubercles I 

 enlarged. '*_ 



A large intestinal and two 

 large gastric spines in the 

 middle line H. spinosus. 



No large intestinal spine : a 

 single gastric tubercle in the 

 middle line H. diacanthus. 



A pair of gastric tubercles in 



the middle line H. aries. 



fa. 

 Gastric re- | 

 gion with- J 

 out tuber- \ 

 cles. I b. 



An erect 

 claw-like in- 

 testinal spine 



No intestinal 

 spine 



H. calvarius. 



H. planasius. 



Hyastentis pleione (Herbst). 



Cancer pleione, Herbst, Krabben, III. iii. 52, taf. lviii. fig. 5. 



Naxia pleione, Gerstaecker. Archiv. fur Naturgesch. XXII. 1856, p. 114, taf. v. 

 figs. 1-2. 



Hyasten/ts pleione, A. Milne- Edwards, Nouv. Archiv. du Mus. VIII. 1872, p. 250. 



Hyastenus pleione, do Man, Archiv. fur Naturgesch. LIII. 1887, p. 225, taf. vii. 

 fig. 3 ; and Journ. Linn Soc, Zool., Vol. XXII. 1888, p. 18. 



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



Hyastenus pleione, J. R. Henderson, Trans. Linn. Soc. (2) V. 1893, p. 343. 



Carapace triangular, elegantly rounded behind, pubescent like the 

 legs and rostrum, the regions well-defined, tuberculated as follows : — 

 six tubercles disposed in a Y or cross on the gastric region, one in the 

 groove between the gastric and the extremely prominent cardiac region, 

 one in the middle of the intestinal region, and three in a line on the 

 boundary of the hepatic and pterygostomian regions ; on either bran- 

 chial region are two longitudinal rows of tubercles, the upper row 

 beiug the more distinct, bnt the last tubercle in the lower row being 

 the largest, and forming a rather prominent epibranchial spine; finally 

 on either side of the groove separating the cardiac and intestinal 

 regions is a prominent tooth. 



The rostrum consists of two slender divergent spines, which in the 

 male are half the length of the carapace proper, but in the female are 

 considerably less. 



The basal antenual joint has its outer margin, anteriorly, bilobed. 



The hairy trunk-legs have the upper surface somewhat uneven or 

 actually nodular. 



The chelipeds in the male are stouter than the other legs, and are as 



