62 Memoirs of the Indian Museum. [Vou. IV, 
The eyes are not greatly expanded. ‘The cornea is much broader than the stalk 
and its greatest breadth is distinctly less than the length of the whole organ. ‘The 
corneal and peduncular axes are at right angles to one another and the anterior margin 
of the ophthalmic somite is produced and at the apex truncate or slightly emarginate. 
In very young specimens, about 30 mm. in length, the corneal index ' is approximately 
45; it increases as the animal grows and is about 7:0 in examples between 80 and 
go mm. in length, while in the largest individual examined it is as much as 8:0, The 
antennular peduncle is shorter than the carapace excluding the rostrum. The mandi- 
bular palp is composed of three segments. 
The outer margin of the merus of the raptorial claw terminates anteriorly in a 
sharp tooth. The carpus is grooved and carinate externally and its dorsal keel is 
furnished with two tubercles, of which the distal is often bilobed ; more rarely there 
are three distinct tubercles. "The merus is somewhat expanded at its distal end in the 
adult male and bears three movable spines and a row of fine pectinations on the margin 
opposed to the dactylus. The dactylus is provided with six curved teeth including 
the apical one ; the external margin is obtusely angled at the base and is strongly 
sinuous in both sexes. The proximal part of the dactylus is shghtly swollen. 
The last three thoracic somites are furnished with sharp submedian and intermediate 
carinae. The fifth somite is bilobed laterally and does not possess any spines on the 
inferior margin. ‘The anterior process consists of a very sharp antrorse spine ; the 
posterior process, which is not so sharp, is directed straight outwards and is less than 
half the length of the anterior. ‘The two marginal lobes of the sixth somite are almost 
equal in length, but the anterior is narrower than the posterior and is obliquely trun- 
cate at the apex. Both lobes of the seventh somite are acute, but the anterior is very 
much shorter and narrower than the posterior. 
There are four pairs of sharp longitudinal carinae on the first five abdominal 
somites and three pairs on the sixth. On the 2nd, 3rd, 4th and 5th between the 
submedian carinae there is a small elongated and transversely-notched median tubercle. 
The following carinae end in spines :— 
Carinae. Abdominal somites. 
Submedian” 36 =. ay 4, 5, 6. 
Intermediate re “i: + (2) 3545/50: 
Lateral : Ae (i) 5 354505510: 
Marginal <a xe A Tee 
The telson bears a close resemblance to that of the species belonging to the guin- 
quedentata group. ‘The median carina is sharp and is very obscurely notched at the 
base ; it terminates in a short spine which overhangs a single blunt tubercle. The 
oblique rows of pits leading to the interspaces of the intermediate marginal denticles 
are distinct and there is also a single longitudinal row on either side of the median 
carina. The submedian, intermediate and lateral teeth are well marked and behind 
! The corneal index :—the number of times the breadth of the’cotnea is contained in the median 
length of the carapace, excluding the rostrum. (See p. 9.) 
Very rarely, in large specimens, the submedian carinae of the third abdominal somite end in spines. 
