224 INDIAN CYPRINID^. 



substances, such as are found in stagnant waters, and in the Gonorhynchs 

 for tearing and uprooting certain kinds of confervoid plants, which form 

 a short slimy covering to the rocks on which they grow in clear mountain 

 streams. ^ 



6. The true Cyprins {Cyp, pi-ojprius Cuv.) together with the Barbels, 

 Cirrhins, and Labes, subsist less exclusively on a vegetable regimen. Their 

 mouths are invariably small, and either directed downward or situated low in 

 the head ; and as far as my inquiries have extended, it is on such modifications 

 of the mouth that we find the length of the intestines and the habits of the 

 different groups to depend. 



7. In the Gudgeons the mouth is formed simply for receiving a 

 kind of food that is obtained in abundance without any effort, and which 

 requires no prehensile teeth or other organs for its collection or preparation 

 before it is submitted at once to the process of digestion. The mouth 

 is consequently small, and is opened and closed chiefly by the muscular 

 structure of the snout ; the jaws are weak, and the lips hard and cartilagi- 

 nous, without sensibility or muscularity, and their intestinal canal varies from 

 eight to eleven and even twelve lengths of the body, including the head and 

 caudal fin ; except in the Hypostomi, Lacep. among fishes, Ostrich among birds, 

 and perhaps some of the ruminants, such development of the abdominal 

 canal is rare, a circumstance which it will be necessary afterwards to recollect 

 when speaking of types. 



8. In the Gonorhynchs the muscular power of the snout is greater 

 than in the Gudgeons ; the mouth is smaller and situated farther back in the 

 lower surface of the head, the lips thicker, and though defended externally by 

 a hard insensible cartilage, are formed for very powerful muscular action. In 

 this genus the length of intestinal canal is usually about eight lengths of the 

 body, and exceeds that of all other Cyprins except the Gudgeons. 



