FISH. (PART I) 



By B. L. Chaudhuri. 



This part contains a systematic treatment of the Sub-orders Selachii and Batoidei 

 of the Order Plagiostomi and of two Sub-orders (Malacopterygii and Ostariophysi) of 

 the Order Teleostei. The total number of specimens examined and recorded in this part 

 is 823, which are found to belong to forty- two species. Of these four are new to science. 

 These forty-two species fall into twenty-five genera belonging to nine different families. 

 The geographical and biological results of my study of the fish fauna of the lake will 

 be discussed on the completion of the systematic notice of the entire collection. 



Order PLAGIOSTOMI. 



Suborder SELACHII. 



Family CARCHARINIDAE. 



Genus PHYSODON, Müller and Henle. 



Physodon mulleri, Müller and Henle. 



1841. Carcharias {Physodon) mulleri, Müller and Henle, Plagiosl., p. 30, pi. xix, fig. 1. 



1878. Carcharias mulleri, Day, Fish. Ind., p. 713. 



1889. Carcharias mulleri, Day, Faun. Brit. Ind., Fish., I, p. 11. 



1913. Physodon mulleri, Garinan, Mem. Mus. Comp. Zool. (Harvard), XXXVI, p. 108. 



One young specimen (female), 355 mm. in total length, was collected at Rambha 

 in March 1914. 



The teeth are not serrated; their cusps are long with broad and somewhat 

 swollen bases, bent towards the angle of the mouth; on the upper jaw there is a 

 small median tooth and there are two small teeth on the symphysis of the lower 

 jaw. The head is broader than deep ; the snout is pointed and is about one- third of the 

 distance from the tip of the snout to the fifth gill-cleft ; the nostrils are very close to 

 the mouth, their distance from it being only one-fifth of the distance from the tip 

 of the snout to the mouth; the mouth is greatly arched; the eyes, which are 

 lateral, are small and are provided with a nictitating membrane at least on the 

 anterior side ; the gill- clefts are wider than the eyes. The second dorsal fin is very 

 small and extends a little further back than the anal fin; there is a distinct pit 

 anterior to the root of the caudal fin. The denticles are very small and numerous. 



To judge from the part of the lake in which it was obtained, it is probable that 

 the species is a permanent inhabitant in the main area. 



Distribution : — Bengal and China. 



