Perilampus. INDIAN CYPRINID.E. 389 



that author of much of the merit to which his labours as a naturalist en- 

 titled him, but the world at large of the masterly elucidation of this subject 

 that might have been expected from the hand of Cuvier. 



Notwithstanding the very general assemblage of forms that Cuvier's 

 definition of the genus Abramis might be supposed to admit, the European 

 species only amount to five, and three of these are peculiar to the tributaries 

 of the Baltic. I found, however, upon a close examination of Indian Ctjpri- 

 nidcB that if we were to content ourselves with the characters given of the 

 Breams by systematic writers, we should not only confound at least two 

 natural groups, but augment our Indian species of that genus to about 

 thirty five in number. 



From this vast accession of materials, for which we are chiefly indebted 

 to Buchanan, I am enabled to distinguish two natural genera, Perilampus and 

 Opsarius, and to suggest something like natural limits to the hitherto ill 

 defined genus Leuciscus. Before entering upon the consideration of any 

 one of these groups, it is necessary to offer a few remarks on their general 

 distinctions. 



The Perilamps, so called from the brilliancy and variety of their colours, 

 as well as the Opsarions, or fish-eaters, seize their prey by means of a sudden 

 effort or spring, for the performance of which the great breadth of fin appears 

 to be accumulated behind. The mouth is armed with a prominent knob 

 on the apex of the lower jaw, more or less sharp in the several species ; when 

 the mouth is closed this knob is received into a corresponding fissure in 

 the upper jaw : thus far the two groups agree, but in the general develop- 

 ment of their forms and structure, nature has assigned to each a totally 

 distinct organization, adapted to the peculiar ends for which the species were 

 designed. Between the two groups here alluded to the Leucisci occur, con- 

 sisting perhaps of species that might be referred on the one side to the 

 Perilamps, and on the other to Opsarions, rather than forming, by any distinct 

 structure or habits of their own, a natural group. 



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