1895.] 
A.. Alcock —Carcinological Fauna of India. 
207 
Chelipeds in the adult male enlarged : the second pair of trunk- 
legs usually very much longer than the 3rd 4th and 5th pairs. 
The abdomen in both sexes consists of seven distinct segments. 
Key to the Indian species of Hyastenus. 
1. Rostral 
spines at least 
as long as the <j 
carapace pro¬ 
per. 
i. Rostral spines as long as the 
carapace, and nearly parallel 
in their proximal half : cara¬ 
pace indistinctly tubercu- 
lated.. .. 
ii. Rostral spines about twice 
as long as the carapace, and 
widely divergent from their 
origin: carapace with nu¬ 
merous tubercles, and with 
large cardiac, branchial and 
intestinal spines : a long ter¬ 
minal spine on the merus of 
of the second pair of trunk- 
legs . 
r 
D enuded 
carap ace 
with nume¬ 
rous tuber- 
c 1 e s, or 
spines, and 
erosions. 
2. Rostral 
spines not 
much more 
than half the 
length of the 
carapace pro¬ 
per. 
i 
Legs coarse, 
the mero- 
podites of 
all (includ--{ 
ing the 
chelipeds) 
nodular. 
m 
cle 
groove 
tween 
gastric 
card 
regions. 
gions, 
ii. Legs slend¬ 
er, the me-j 
ropodites ' 
smooth. 
[LL seise. ] 
H. tenuicornis. 
a. Numerous 
tubercles for¬ 
ming a cross 
on the gastric 
region: a me¬ 
dian trans¬ 
verse tuber- 
the 
be- 
the 
and 
i a c 
H. pleione. 
b. Gastric re¬ 
gion almost 
smooth: no 
tubercle 
tween 
gastric 
cardiac 
be- 
the 
and 
re- 
H. hilgendorfii. 
a. Carapace 
elongate 
closely cover¬ 
ed with gra¬ 
nules and tu¬ 
bercles, with¬ 
out spines. 
i. Conspicuous¬ 
ly large spines 
on the cardiac 
and branchial 
H. oryx. 
regions. 
H. gracilirostris. 
