1920.] S. L. HORA : Indian Homalopteridae. 207 



Insertion of the dorsal fin in front of the ventrals. Fifteen 

 pharyngeal teeth on either side. Colour reddish, 

 with a brown stripe from the margin of the eye to 

 the base of the dorsal fin ... ... ... H. bilineata. 



Homaloptera modesta (Vinciguerra). 



1889. Helgia modesta, \'inciguerra, Ann. Miis. Star. Nat. GenoTa, 

 XXIX, p. 326. 



Geographical Distribution '.—Upper Tenasserim. 



Homaloptera bilineata, Blyth. 



i860. Homaloptera bilineata, Blyth, Journ. As. Sac. Bengal, XXIX, 



p. 172. 

 1869. Nemachihis sei'pentanus, Day, Proc. Zool. Sac, London, p. 551. 

 1878. Homaloptera bilineata, Day, FisJies of India, II, p. 526. 

 1S89. Homaloptera bilineata. Day, Fauna of British India, Fish I, 



1889. Homaloptera bilineata, Vinciguerra, Ann. Miis. Star. Nat. 

 Genova, XXIX, p. 332. 



Good descriptions of this species are given by Vinciguerra and 

 other ichthyologists and as I have examined only one specimen 

 in a ver}'' bad state I do not attempt to give an account of this 

 animal except to describe a scale. 



A scale from the base of the dorsal fin is pear-shaped with a 

 central nucleus. There are a large number of circular striae running 

 circumferentiall3\ There are about 20 near the base and half that 

 number towards the apex, the interspaces being consequently wider 

 near the apex than near the base. There are only two complete 

 radii to the apex and about 3 short ones in the other direction. 



Geographical Distribution : — Tenasserim districts, Burma. 



Fam. CYPRINIDAE. 



Subfam. CYPRININAE. 



Genus Psilorhynchus, McClelland. 



As the species of this genus are often confused with those of 

 Homaloptera I have included a revision of the genus in this paper. 



This genus is abundantly distinct from the Homalopteridae 

 and cannot be distinguished from the C3-prinidae by any valid 

 character. From the former it is distinguished by the possession 

 of an air-bladder consisting of two parts arranged longitudinally 

 and not enclosed in a bony capsule, by the structure of the 

 pharyngeal bones, bj- the possession of large well-developed 

 scales in the adult and by the less extreme modification of the 

 paired fins. 



It ma}^ be defined as follows : — 



A genus of Cyprininae consisting of small fish modified for 

 Ufe in mountain torrents. The head and body are but slightly 

 depressed, but the ventral surface is flattened and the chest 

 highly muscular. The paired fins are expanded but not greatly 



