360 Records of the Indian M itseuvi. [Vol. XII, 



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 an 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 rudimentar}' 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 fringed 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 o"4XO'3 mm. in longer and shorter diameter. 



Pontophilus incisus 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. incisiis, 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. incisus, 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. sctdptus 

 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 comparatively 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. sculptus from the 

 Irish Sea, 



■^ Kemp, Rec. lud. Mus., VI, ]). m f loi i i 



