64 Records of the Indian Museum. [Vol. XXIV, 



name Diplophysa , is not available in Calcutta, so I take from Day ' 

 the characters on which this genus was erected. The genus Diplo- 

 physa comprises those fishes in which the body is greatly elongated 

 and strongly compressed posteriorly ; the eyes are surrounded with 

 a fold of skin forming a lid; the lips are fleshy, the upper more or 

 less denticulated, the inferior bilobed and more or less papillated 

 and the air-vessel is divided into two parts, the anterior enclosed 

 in a bony capsule and the posterior elongated and free in the 

 abdominal cavity. I agree with Day (op. cit.) that the first three 

 characters do not possess any generic value, but the last feature, 

 that of the air-vessel, is quite sufficient to distinguish the genus 

 Diplophysa from Nemachilus, to which it is closely allied. Day 

 did not dispute the validity of the last character but suggested a 

 re- examination of the Western Turkestan specimens and remarked 

 that, " it would be very remarkable were the N emacheili found in 

 Europe, in fact throughout Asia, even in the Oxus, to have their 

 air-vessel enclosed in bone, whereas in the river Hi going to Lake 

 Balkash, and the river Urdjar falling into Dake Ala (Ala-Kul), to 

 have the same organ partially free in the abdomen, as is seen in 

 the genus Botia." Day did not think himself justified in recognis- 

 ing Diplophysa as a distinct genus from Nemachilus even on the 

 character of the air-bladder, which is so remarkable. 



Kessler 2 in 1879, when dealing with the Central Asiatic fishes, 

 upheld his genus Diplophysa and described two new species under 

 this generic designation. In reviewing Day's criticism of the 

 genus he pointed out that in all probability Dr. Stoliczka's collec- 

 tion was made in the area south west of the Tarim river-system, 

 while Przewalski's collection,. which contained several representa 

 tives of the genus, was made) much further to the east. Moreover 

 he considered the air-bladder to be as important for taxonomic 

 purposes as the pharyngeal teeth, on which the two families 

 Cobitidae and Cyprinidae are distinguished. 



Herzenstein 3 in his valuable monograph of Central Asiatic 

 fishes agreed with Day and considered Diplophysa synonymous with 

 Nemachilus. But at the same time he instituted a new genus 

 Lefua to accommodate Diplophysa costata Kessler and Octonema 

 pleskei Herz. He characterized the genus Lefua as follows •. — 

 " Caput valde depressum. Os fere terminale. Spina suborbitalis 

 nulla. Nares anteriores cirro sat longo instructae. Cirri rostrales 

 4, supra-maxillares 2. Vesicae natatoriae pars posterior in cavitate 

 abdominali libere suspensa." No notice seems to have been taken 

 of this genus till 1907 when Berg* recognised it and considered the 

 J apanese genus Elixis Jordan and Fowler 6 as a synonym of 



1 Day, Proc. Zool. Soc. London, p. 793 (1876) ; Sci. Pes. 2nd. Yavkand 

 Mission, Ichthyol., p. 12 (i8/S>. 



2 Kessler, Bull. Acad. Sci. St. Pctersbourg XXV, p. 302 (1879). 



' A Herzenstein, Wiss. Pes. Pi-zeivalski Central As. Pet's., Zool. Ill (2), p. 1 

 (1888). 



* Berg, Proc. U.S. Nat. Mils. XXXI 1, p. 437 (1907). 



6 Jordan and Fowler, Proc U.S. Nat. Mus.X.XV\, p. 768 (1903). 



