360 Records of the Indian M useum. [ VOL. ET; 
transverse for the most part ; but there is a sharp longitudinal mid- 
dorsal carina in the posterior three quarters of the third somite, 
a pair of juxtaposed carinae, fused posteriorly , in the same position 
on the fourth somite and a similar pair of carinae, slightly diver- 
gent posteriorly, on the fifth. On the sixth somite the only sculp- 
ture consists of a pair of longitudinal carinae separated by a broad 
flat interspace. The pleura of the first four somites are pointed 
below, bluntly in the female, rather more sharply in the male. 
The pleopods show marked sexual differences. In the male 
the endopod of the last four pairs is comparatively well developed 
and possesses al appendix interna. In the female the endopod is 
reduced in size and is extremely small in the case of the last pleo- 
pod: the appendix interna is present in the second pair, but is 
much smaller than in the male; in the third and fourth pairs it is 
quite rudimentary and from the fifth it is entirely absent. 
The outer uropod is shorter than the inner and is very slender, 
nearly four times as long as broad. The telson is scarcely longer 
than the inner uropod and is also very slender, It is sulcate 
above and bears two pairs of small dorso-lateral spinules. The 
lower edges are {ringed with long setae and distally it terminates 
in a sharp point, flanked by a pair of short spinules and bearing 
two pairs of long ‘finely plumose setae. 
Large females reach a length of 18 mm.; the males are smaller, 
not exceeding 15 mm., and are apparently much less abundant. 
The eggs are about 0'4 X0°3 mm. in longer and shorter diameter. 
Pontophilus incisius is a remarkably close ally of P. sculptus, 
Bell, a species known from the Mediterranean and from the French 
and British coasts.! In all conspicuous characters there is a very 
close similarity between the two forms, but differences in detail are 
sufficiently numerous to justify their specific separation. In P. 
incisus there is only one strong tooth in the mid-dorsal line of the 
carapace, whereas in P. sculptus there are almost invariably two. 
In P. incisus, also, the antennal scale is narrower and the tooth 
on its outer margin is placed near the base instead of in the mid- 
dle. In both species the spine on the outer margin of the merus 
of the first peraeopods is terminal and not sub-terminal as in some 
other species of the genus; in P. tncisus, however, the anterior 
edge of the merus between this spine and the articulation of the 
carpus is entire, bearing only a few hairs, whereas in P. sculptus 
two or three additional spines are found in this position. In 
P.incisus, moreover, the lateral process of the antennular peduncle 
is more pointed distally, the subchela is more slender, the palm 
of the second peraeopods shorter and the dactyli of the last two 
peraeopods CUE SEES longer. 
In a previous paper? I have remarked on the presence of the 
appendix interna in P. sculptus ; but I failed to notice that in the 

' I have compared the Indian species with specimens of P. scu/ptus from the 
Irish Sea. 
* Kemp, Rec. Ind. Mus., VI, p- 10 (1911). 
