1895.] A. Alcock — Carcinological Fauna of India. 203 
The external maxillipeds have the ischium and merus somewhat 
concave. 
The chelipeds vary according to sex. In the adult male they are 
longer than the carapace and rostrum, and are far stouter than any of 
the other legs : the carpus is enlarged and sculptured, the palm is 
broadened, as well as somewhat carinate along both edges and strongly 
produced at the postero-inferior angle, and the fingers are opposable in 
their distal half only : in the female and young male they are shorter 
than the carapace with the rostrum, and are hardly stouter than the 
other legs ; all the joints are subcylindrical, and the fingers are apposa- 
ble in the greater part of their extent. 
In both sexes, the merus of all the legs, including the chelipeds, 
has a spine or tooth at the far end of its upper margin. The 2nd pair 
of trunk-legs, which are the longest, are, in the male, nearly twice the 
length of the carapace and rostrum, but in the female are considerably 
shorter. 
hoc. Andaman Sea, 130 to 561 fathoms. 
Scyramatliia rivers-andersoni, n. sp. 
Carapace closely covered with peg-shaped hairs with long setee 
interspersed : legs with few setee. The carapace, which is pyriform and 
somewhat inflated, has, besides a supra-ocular tooth and a sharp post¬ 
ocular process, and besides a salient hepatic spine, and a still more 
salient lateral epibranchial spine (about two-fifths the greatest breadth 
of the carapace in length) six sharply conical tubercles evenly and 
equidistantly arranged in a circle round a central caradiac tubercle: 
of these the most posterior overhangs the middle of the posterior border, 
while the most anterior, which is situated far back on the gastric 
region, is flanked on either side by a very faint eminence. 
The rostrum consists of two slender divergent horns, the length 
of which in the male is about three-quarters, in the female about 
two-thirds, that of the rest of the carapace. 
The eyes are small, and though freely movable forwards are not 
retractile backwards further than to impinge against the summit of 
the post-ocular process of the carapace. The basal antennal joint, 
which is of no great width, is sharply truncated: the mobile portion of 
the antenna is freely exposed on either side of the rostrum. 
The chelipeds in the fully adult male (but not in the young male) 
are much stouter than the other legs, and are as long as the carapace 
and rostrum ; their merus is prismatic with knife-like edges, the upper 
edge ending in a spine ; their carpus is bicarinate, the outer carina 
being very prominent; the hands, which form nearly half their total 
J. ii. 26 
