356 



Records o/ the Indian Museujii. 



[Vol. XII. 



and four from Port Blair in the Andamans. One of the new forms, 

 P. incisus, is a very close ally of the Atlantic and Mediterranean 

 P. scuiptus, the remainder are sharply distinguished from all species 

 previously described by well-marked characters found in the sculp- 

 ture of the carapace and abdomen and in the form of the rostrum , 

 lateral process of the antennule, antennal scale and first two pairs 

 of legs. 



In some of the species there are considerable differences be- 

 tween the sexes in the form of the last four pairs of pleopods, a 

 feature discussed in detail on p 381, and other sexual distinctions of 

 an unusual nature are met with in P. lowisi and P. candidus. In the 

 former the antennal scale, which is remarkable for the possession 

 in both male and female of a series of spinules on its outer margin, 

 shows wide differences in form in the two sexes. In the latter a 

 conspicuous spine in the mid-dorsal line of th3 carapace is present 

 in the male and absent in the female, a remarkable distinction when 

 the great constancy of the armature of the carapace in other spe- 

 cies is remembered. 



The ten Indian species of Pontophilus may be distinguished 

 thus : — 



I. — First peraeopods with rudimentary exopod ; second pe- 

 raeopods verj' short, not reaching distal end of merus 

 of first pair, ti.fir chela well formed with curved 

 fingers ; lateral urocess of antennular peduncle styli- 

 form, much longer than broad. 



A. Median carina of carapace with two spines ... gracilis. Smith. 



B. Median carina of carapace with three spines ... (T^v^^?. Smith. 



II. — First peraeopods without exopod ; second peraeopods 

 longer, reaching beyond carpus of first pair, their chela 

 ill-formed with parallel fingers; lateral process of an- 

 tennular peduncle not styliform, usually subquadrate 

 and broader than long. 



A. A median longitudinal carina on carapace and 

 on 3rd, 4th and 5th abdominal somites [ros- 

 trum bread distally, anterior margin squarely 

 truncate or concave]. 



1. Outer margin of antennal scale armed with a 



spine or a series of spinules in addition to 

 a terminal spine. 



'I. Carapace with five carinae bearing- spines; a 

 single additional spine on outer margin of 

 antennal scale, placed near base ; merus of 

 first peraeopods with a single spine at distal 

 end of outer margin ; first four abdominal 

 somites with strong lateral sculpture 



b. Carapace without spines and without lateral 

 carinae ; a series of spinules on outer margin 

 of antennal scale ; merus of first peraeopods 

 with three spines at distal end of outer mar- 

 gin ; lateral sculpture of first four abdomi- 

 nal somites feeble 



2. Antennal scale without additional spines on 



outer margin ; [rarapace with spines and 

 lateral carinae ; first four abdominal somites 

 with strong lateral sculpture.] ... 

 B. No median longitudinal carinae on carapace or 

 abdomen. 



incisiis, sp. nov, 



lowisi, sp. nov, 



<nbsectiofa, Kemj). 



