INDIAN CYPRINIDZ. 227 
forms; but this hook more or less developed, is characteristic not merely of 
the Opsarions, but of the sub-family (Sarcoboring) to which they be- 
long. It is received into a corresponding depression in the apex of the 
upper jaw when the mouth is closed. The back is straight, the dorsal is 
placed opposite to a long anal, both fins being situated near the caudal 
extremity, by which the power of darting or springing is rendered most 
perfect.* The abdominal cavity is long, and is chiefly occupied by a straight 
stomach of equal length, which is divided by a strangulation from a short 
fleshy intestine connecting the stomach directly with the vent, without any 
convolutions or elongation of the tube. 
16. “ The energies of nature,” to use the words of Mr. Swainson, “ are 
here concentrated as it were to the production of that form most adapted for 
one especial purpose,” that of springing on their prey like the Feline or 
eats, which they seem to represent. It is no uncommon thing to find an 
Opsarion so overgorged that the tail of its prey remains protruding from 
the mouth, to be swallowed after that portion which is capable of being 
received into the capacious stomach is sufficiently digested to admit of the 
introduction of the remainder. + 
17. Two other genera of this sub-family remain to be noticed; viz. Sys- 
tomus and Leuciscus. The first is made up chiefly of small species named 
Puneti by the Indian fishermen. If we were merely guided by their general 
* The principal instrument of progressive motion in fishes is the caudal fin; other fins, as 
shewn by Roget, are mere auxiliaries, serving to balance the body while it receives propulsion from 
the tail. Vide Bridgewater Treat. i. 286. This is correct in regard to fishes in general, but in the 
Opsarions and Perilamps the dorsal and anal, from their position and size, contribute greatly to their 
velocity, being also situated on or near the tail, thus increasing the caudal surface, which, as Roget 
justly observes, operates as an oar does in sculling. 
+ I have seen Opsarions so often in this state, that I presume they are easier caught in it than in 
any other. A similar power of deglution is recorded of sea-gulls by Blumenbach. 
