2Ôo Memoirs of the Indian Museum. [Vol,. V, 



sides of the fifth somite are strongly convex, while those of the sixth are concave in 

 the anterior three-quarters of their length. The sixth segment is widest posteriorly. 



The telson is a little broader than long (pi. xiii, fig. 7) ; its lateral margins are 

 somewhat convergent and the apex is noticeably emarginate. On the upper surface 

 there is an obscure fl-shaped ridge, the extremities of the H being directed towards 

 the postero-lateral angles. In the middle line there is an obscure sulcus and on 

 either side, external to the (1-shaped ridge, there is a well-marked longitudinal 

 groove. On the dorsal surface of both inner and outer uropods there are two blunt 

 ridges. 



A large male is only 23 mm. in length. 



Upogebia heterocheir appears to differ from all known species of the genus in the 

 remarkable sexual differences in the first pair of legs and, apart from this feature, is 

 distinguished by the position of the spines on the leg-segments and other characters, 

 in the Chilka Lake it is probably abundant; but, owing to its burrowing habits, it 

 was difficult to obtain any number of specimens. It is, however, represented in our 

 collection by thirty- two individuals, mostly small, and a number of cast skins. 



The species is a permanent inhabitant of the lake ; it was found both in the main 

 area and in the outer channel at all seasons of the year, in water of specific gravity 

 varying from i - ooo to 1/0265. It seems to prefer a bottom composed of mud with a 

 considerable admixture of sand and it was on ground of this character near Nalbano 

 and off Barhampur I, that the majority of our specimens were obtained. In several 

 localities cast skins were taken in abundance and it is evident that the act of exuvia- 

 tion is performed simultaneously by a large number of individuals. Cast skins were 

 found in February and in September; it is probable, therefore, that there are at 

 least two moulting periods in the course of the year. 



Ovigerous females were found only in the months of November and December, 

 in water of specific gravity varying from rooi to 10125. The eggs are large, about 

 o - 74 mm. in longer diameter. 



The type specimens are registered under no. 9304/10. 



DECAPODA NATANTIA, 



Tribe CARIDEA. 

 Family CRANGONIDAE. 

 Genus PONTOPHILUS, Leach. 



1912. Pontophilus, Kemp, Rec. Ind. Mus., VI, p. 8. 



In the paper quoted above I have endeavoured to show that the genera Pontophi- 

 lus, Leach, and Philocheras, Stebbing, must be united, the former name having pri- 

 ority. Though such extreme forms as spinosus (Leach) and echinulatus (M. Sars) are 

 readily distinguished by several features which at first sight seem of generic value, 

 there exist species almost precisely intermediate in character. Any division into two 

 genera must, I believe, be of an arbitrary nature and can only tend to obscure the 

 affinities of the species comprised in the series. 



