208 
A. Alcock — Carcinological Fauna of India. 
[No. 2, 
fi¬ 
ll. Denuded 
carap ace 
smooth and 
polished,*} 
with a few 
large 
spines. 
2 . 
Carapace 
triangular, 
with a large 
e p i branchial ( 
'spine and at<} 
least one large 
sub-hep a t i c 
tub ercle on 
either side. 
l. 
A large intestinal and two 
large gastric spines in the 
middle line. 
li 
a 
No large intestinal spine : 
single gastric tubercle in the 
middle line.. 
Carapace 
elongate, 
with a small 
e p i b ranchial 
tubercle, and ■{ 
with none of 
the sub-hepa¬ 
tic tubercles ! 
enlarged. y 
i. A pair of gastric tubercles in 
the middle line. 
f a. An erect 
ii. Gastric re- | claw-like in- 
gion with-J testinal spine 
out tuber- 'j 
cles. j b. No intestinal 
f spine. 
H. spinosus. 
H. diacanthus. 
H. aries. 
H. calvarius. 
H. planasius. 
Hyastenus pleione (Herbst). 
Cancer pleione, Herbst, Krabben, III, iii. 52, taf. lviii. fig. 5. 
Naxia pleione, Gerstaecker. Archiv. fur Naturgesch. XXII. 1856, p. 114, tab v. 
figs. 1-2. 
Hyastenus pleione, A. Milne-Edwards, Nouv. Archiv. du Mus. VIII. 1872, p. 250. 
Hyastenus pleione, de 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 
being the more distinct, but 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 antennal 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 
