INDIAN CYPRINID^. 



225 



9. The development of the intestinal canal in Cyprinidee differs with the 

 habits of species, so as to afford something like a basis for true distinctions 

 between the different genera, and is fortunately connected with such pe- 

 culiarities of form and colour, as to render it easily available as a guide to 

 an improved method of classification. 



10. The philosophical views of Mr. MacLeay regarding the circularity 

 of groups, left it almost certain that the law which applied to other 

 classes might be also applied to fishes ; and as the essence of that law consists in 

 the tendency of the contents of natural groups to form a circle, it became 

 highly probable that as strictly herbivorous Carps were known, so on the 

 contrary carnivorous species might be expected also to exist.* This is exem- 

 plified by a comparison of typical with subtypical groups, as Quadrumana 

 with Ferce in the orders of Mammalia, and Insessores with Raptores in 

 the orders of birds ; as this is true with regard to higher groups, it should 

 be just as applicable to the lower assemblages when they happen to be 

 equally complete in their parts. 



11. The above inference whether its principles be just or not, has proved 

 to be perfectly correct, notwithstanding the remark of Linnaeus that Cyprins 

 are perhaps the least carnivorous of the whole class of fishes, " feeding chiefly 

 on seeds, grass, and even mud ;" and the observation of Cuvier " that they 

 are the least carnivorous of all fishes." Those who have since written on the 

 subject have for the most part adopted the views on this point of the great 

 authorities just named. 



12. A close investigation of our Indian species has led to very dif- 

 ferent results, and enabled me to form Cyprinida into three sub-ftimilies. 

 First the Pceoiiomince or herbivorus Cyprins already adverted to, which 



* I here refer particularly to what iMr. MacLcay calls affinity of transiiltation, or that relation 

 which tlie opposite points of a circle of allinities bear to each other. 



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