xcvi Proceedings of the Asiatic Soc. of Bengal. [June, 1914.] 



than that of the rest of the lake. The fauna, which we are 

 now investigating in detail, consists of a mixture of marino 

 and fre-h water types with a crrtain element that appears to 

 be peculiar to brackish water. Among mammals Orcella brevU 

 rostris and Lutra macrodus are commoir. Crocodiles, mann3 

 turtles and the mud-iuitle Ivmyda qranosa intermedia^ with a 

 species of Hydrophis, Cerberus rhyncops and Chp.rshydrus 

 granulatas, iepresent the reptiles Fish, including several 

 species of shark and ray, are numerous, the great majority 

 belonging to small species. Prawns of the family Ptneidae 

 occur in great abundance, together with forms so charac- 

 teristic of freth water as Caridina ; except in the outer channel, 

 the crabs are poorly represented. Of the other Crustacea, 

 four species of Rlysidae hove been found, three of Stoma to- 

 poda and large numbers of Amphipoda, Isopoda, etc. Most 

 of the molluscs are small and, except in the outer channel, a 

 large proportion are noteworthy on account of their extremely 

 delicate shells. Several of the Polvzoa and coelenterates have 

 already been found in brackish water in the Gangetic delta ; 

 others are new to science. The sponges include representa- 

 tives of three genera— Spongilla, a characteristic freshwater 

 genus, and Subcritcs and Cliona, a^5 characteristically marine. 

 The first two a?tually grow together and similarities in their 

 biolo.y have been observed. The b- ring sponge Clicna is 

 found in the shells of the larger Lamellibranchs and Gastrop ds. 

 An account of the fauna will bo published later in the 

 Memoirs of the Indian Museum. 



Dr. E. P. Harrison exhibited the cc Gore Effect M in iron. 



i 



The read ng of the following papers was postponed : 



1. Note on the application of the principle, of Isostatic 

 compensation to the conditions prevailing benenlk the Indo-Gan- 

 gttic alluvium.— By H. H. Uxydes, C.I.E., D.So. 



2. Action of Nitric Oxide on Metallic Peroxides suspended 

 in water, lart I.—By Bauun Chandra Dutt and Sukya 

 Naua van Sen. Communicated by the Physical Science 5. crdary. 



3. Contributions from the Chemical Laboratory, Presidency 



College : 



(a) Nitrites of the Su'plwrium Bases, Part I.—Trimethyl 

 sulphorium Nitrite.— By R asik Lal Datta. Communicated' by 



Dr. P. C. Ray. 



(6) A new method for the preparation of Colloids.— By 



Jsanendranath Mukiiopadhyaya. Communicated bu Dr. 

 P. C. Ray. J 



tantomerism 



helpful 



, By Prafulla Chan- 

 dra Ray. Communicated by Dr. P. C. Ray. 



