1916.] Fauna of the Chilka Lake : Fish. 455 



upper corner of the base of the pectoral fin, over parts of the operculum and on the 

 sides of the abdomen. Many of the bigger specimens are full of mature eggs. One 

 specimen collected from the edge of the lake at Satpara in the month of September, 

 "measuring twenty-five millimeters in length, had a cluster of about forty eggs with 

 growing embryos inside most of them. This egg-cluster was attached between the ends 

 of the ventral fins and the beginning of the anal fin. There are numerous hooklets 

 round each of the capsules of the eggs, which give them a characteristic appearance 

 somewhat like a miniature model of the fruits of the well-known Datura. The anal 

 papila is flat, thick and leaf -like, with a notch in the middle. 



Äs Tate Regan has conclusively shown {Ann. Mag. Nat. Hist., (8), VII, p. 324) 

 the genus Oryzias of Jordan and Snyder is a synonym of Aplocheilus, M'Clelland, 

 afterwards definitely restricted by Bleeker to the group to which it is now applied. 

 Examination of a large number of A . melastigma has led me to suspect that A . latipes 

 (Temminck and Schlegel), the type of the genus Oryzias of Jordan and Snyder, is in 

 all probability identical with A. melastigma. This suspicion has been confirmed by 

 the same species being found among a collection of small fish made by Dr. N. Annan- 

 dale, in September 1915, in the outskirts of Shanghai. Günther, in a manner, long 

 ago comprehended the identity of these two species. Though he omitted A. melas- 

 tigma, M'Clelland, from his Catalogue of Fishes in the British Museum as a doubtful 

 species, he adopted its synonym H. cyanophthalmus , Blyth, as a valid one. The col- 

 lection, on the examination of which he based his identification of Blyth' s species, 

 came from Calcutta, but his difficulty was that the fin had nineteen anal rays only as 

 in A . latipes and not twenty- two. Though most of the Chilka specimens have twenty- 

 two anal rays, I find that some have eighteen, twenty or twenty-one. In other 

 respects they are almost alike. Recently this Museum has received a valuable collec- 

 tion of representative fish from Lake Biwa, Japan, in excellent condition, from the 

 Rinko Zikkensho of Otsu. In this collection there is one specimen labelled Oryzias 

 latipes (Temm. and Schleg.) which appears to us to be a perfectly typical example of 

 A. melastigma , M'Clelland. The acquisition of specimens from Lake Biwa and Shan- 

 ghai has given us an opportunity to institute a close comparison between the Japan- 

 ese specimen and those from Shanghai and the Chilka Lake. The result of this 

 examination is tabulated below : — 



