262 A. Alcock —Ccircinnlogical Fauna of India. [JNfo. r 2, 
gonal, the anterior and posterior borders of both joints sharply laci- 
niate or serrate, as is also the outer edge of the carpus. 
Key to the Indian species of the sub-genus Platylambrus. 
1. Infra-orbital lobe entire and 
strongly produced at the in¬ 
ner (inferior) angle to form 
a great spine plainly visible 
from above on either side of 
the rostrum.... L. prensor. 
2. Infra-orbital lobe deeply 
cleft, the inner portion not 
or hardly visible from above L. carinatus, Edw. 
II. Carapace covered with great mushroom-like or paxilliform 
tubercles : chelipeds with their surfaces very strongly 
spinate or tuberculate: ambulatory legs strongly 
spiniferous.... L. ecliinatus. 
Lambrus (Platylambrus) prensor , Herbst. 
Lambrus prensor , Herbst, Krabben, II. ii. 170, tab. xli. fig. 3. 
Lambrus prensor , Milne-Edwards, Hist. Nat. Crust., I. 358. 
Lambrus jourdainii, P. de B. Capello, Jom. Sci. Lisb., III. 1870-71, tab. 3, fig. 6. 
Lambrus prensor, A. Milne-Edwards, Nouv. Archiv. du Mus., Vol. VIII. 1872, 
p. 260 (foot-note); and Miss. Sci. Mex., Crust., I. p. 147 (foot-note). 
Lambrus prensor , Walker, J. L. S. Zool., Yol. XX. 1890, p. 109 (name only). 
Our numerous specimens correspond exactly with Capello’s figure 
and succint and graphic description. M. A. Milne-Edwards at first as¬ 
signed Capello's species to L. carinatus , Edw., but afterwards to L. pren¬ 
sor, and it is this last authority that I now follow. 
Carapace broader than long, broadly triangular with the sides round¬ 
ed : the median and branchial regions are strongly prominent, the former 
having three small spinules in the middle line, the latter having each 
two oblique granular ridges, one of which is very faint and runs to the 
large lateral epibranchial spine, the other of which forms a strong carina, 
and runs to the large spine at the postero-lateral angle. The antero¬ 
lateral margin is armed with 7 or 8 nearly equal-sized close-set compress¬ 
ed teeth, behind which, at the lateral epibranchial angle, is a very large 
blade-like spine: behind this again, on the postero-lateral border are two 
large teeth, the outer of which, at the postero-lateral angle, is nearly as 
large as the lateral epibranchial spine ; and lastly on the posterior bor¬ 
der are three large curved spines. 
The rostrum is acute, concave at base, and slightly recurved at tip : 
on either side of the rostrum is seen from above a very strong and 
acute spine formed by the prolongation of the inner margin of the 
infra-orbital lobe—this lobe is entire. 
I. Carapace with three dis¬ 
tinct caringe, one median, and 
one, oblique, on either side : 
chelipeds with their sur¬ 
faces (but not their edges) 
for the most part smooth: 
ambulatory legs, with few 
spines. 
