Records of the Indian M^iseuni. 



[Vol. VI. 



is sulcate above and very long, extending beyond the distal end of 

 the outer uropods. In addition to two pairs of dorso-lateral 

 spinules, there is another pair defining the outer angles of the 

 narrow apex. Between the two latter spinules there are four long 

 setae. 



The eggs measure about '51 X •33 mm. in longer and shorter 

 diameter. 



The above description was drawn up from a single ovigerous 

 female, only 9-3 mm. in length, which was obtained by the Marine 

 Survey at S. Sentinel Island, iVndamans (Regd. No. ^V'^.) 



Pontophihis sahsechota is one of the smallest Macrura known. 

 It may easily be distinguished from all species hitherto described 

 by the details of the carination and spinulation of the carapace. 



The mutual affinities of Pontophilus and Philocheras. 



The separation of the genera Pontophihis and Philocheras is 

 almost an impossibility in the case of the species inhabiting Asiatic 

 waters, and, as I have had an opportunity of examining a number of 

 the species which occur in this region, the following notes bearing 

 on the generic status of the forms concerned may be found useful. 



In addition to those preserved in Calcutta, I have been able, 

 thanks to the good offices of Mr, R. Etheridge, Curator of the 

 Australian Museum, to examine the types of three very interesting 

 species described in 1902 by Messrs. Fulton and Grant, and I have 

 also added a few notes, which were kindh^ supplied me by Dr. 

 W. T. Caiman, concerning vSpence Bate's Crangon inter niedius , the 

 only known example of which is preserved in the British Museum. 



In the N. E. Atlantic the two genera may, with one important 

 exception, be distinguished from one another b^' the use of the 

 following characters : — 



Pontophilus. 



Basal process of antennular 

 peduncle sharply pointed dis- 

 tally. 



First peraeopods with small 

 exopod. 



Second peraeopods very 

 short, not reaching to distal 

 end of merus of first pair ; 

 chela well-formed with palm of 

 good length ; fingers concave in- 

 ternally, meeting only at tips. 



Endopod of last four pairs 

 of pleopods only a little shorter 

 than exopod and with appen- 

 dix interna at base. 



Philocheras . 



Basal process of antennular 

 peduncle distally truncate or 

 rounded. 



First peraeopods without 

 exopod. 



Second peraeopods reaching 

 at least as far as distal end of 

 carpus of first pair ; chela weak 

 with palm very short; fingers 

 parallel internally, meeting 

 throughout their length. 



Endopod of last four pairs of 

 pleopods little, if at all, more 

 than half length of exopod 

 and without appendix interna 

 at base. 



