230 



INDIAN CYPRINIDiE. 



other Sarcohorines. As we advance in this sub-family from the Systems towards 

 the Opsarions, we find as has been shewn, the abdominal tube diminishing 

 in length, and in proportion as this takes place, and the habits of species 

 become more carnivorous, we observe the brilliancy of the colours becomes 

 more remarkable. 



£2. The Perilamps, as already stated, are followed by the Leuciscs. In 

 these the diversity of colour is not great, but is compensated for by the 

 metallic brilliancy of the nacre, or silvery pigment with which the scales 

 and opercula are covered, and from which the genus has derived its name 

 Leuciscus, Abies, or white fishes, though not applicable to all the species ; 

 for there is one which is marked on each side with the bright longitudinal 

 streak of the Perilamps, and like the blending of the markings already 

 observed between the Pceonomhice and Sarcoborincs the species in ques- 

 tion, Leucisctcs lateralis,^' seems to unite the white fishes with the Perilamps. 



23. The Perilamps in their structure naturally follow the Systoms, and 

 present numerous bright longitudinal lines of various colours, but particularly 

 blue on their sides. They are all small species of little or no direct utility to 

 man, nor is it possible to account for the peculiar brilliancy of their colours in 

 any other way than as an instance of that inscrutable design, by which it 

 would seem that in pursuit of aquatic insects on which they subsist along 

 the surface of waters, they become the better marks for Kingfishers, Skimmers, 

 Tern, and other birds which are destined to keep the number of fishes in 

 check, especially in deep waters beyond the reach of the waders.f 



* Cyp. Daniconius. Buch. which appears to me to be identical with Cyp. Anjano, id. ; but if 

 not, the latter species on account of certain peculiarities about the mouth, which seem to be 

 wanting in the former, must be referred to the Perilamps. 



t See remarks on P. perseus in a subsequent part of this paper. 



