116 Mr. J. McClelland on Indian Cyprinida?. 



wise be liable to be passed over unobserved ; I am therefore 

 disposed to pay little regard to such objections. The number 

 of species and groups are now so much multiplied in every 

 department of natural history, that detached descriptions are 

 daily diminishing in value ; and besides, it is so easy to make 

 a new genus if not required to show our reason for doing so, 

 that we need not be surprised that it should now have become 

 a regular trade, and that many acquire a temporary fame with 

 the unthinking part of mankind by the practice. 



40. The first test of a natural group is the circularity of its 

 contents. To ascertain whether the affinities of the Cypri- 

 nidce are circular, it is necessary to recollect that the herbivo- 

 rous Cyprins are characterized by their plain colours and great 

 length of intestinal canal, which varies from six to twelve 

 lengths of the body in the different groups $ those with the 

 shortest intestine (the Barbels) being in the centre of the sub- 

 family, it follows that the two extremes must meet, or show a 

 tendency to approximate or close. The herbivorous Carps 

 are united to the Sarcoborince by means of the Gonorhynchs 

 and Systoms, and show, like the last, a tendency to form a 

 circle of themselves, though it is probable that the group 

 is yet far from being complete. The Sarcoborince and the 

 Loaches are united by two new types, the Platycara and Psi- 

 lorhynchus; and the Schistura, in addition to approximating 

 to the Platycara, unites, or shows a tendency to unite, both 

 in form and habits, with the Pceonominte, the group with which 

 we set out ; thus exemplifying the first principle of natural 

 classification, namely, that every natural series of beings, in 

 ifs progress from a given point, either actually returns, or 

 evinces a tendency to return again to that point, thereby 

 forming a circle*. 



41. The second test of a natural group relates to the num- 

 ber of its types. On this point there exists some difference 

 of opinion among writers on the natural system, which their 

 profound inquiries are now doing much to remove. It is a 

 question which, to understand sufficiently for practical pur- 

 poses, requires an extensive knowledge of natural history, and 

 a mind somewhat more imbued with the spirit of philosophy 

 than has hitherto been considered requisite in those who ven- 

 tured to name new genera. It has already been said that the 

 lower jaw of the [Labeos agrees with that of the Cirrhins, in 

 being formed of two bones articulated behind to the anterior 

 process of the preoperculum, and that in front a transverse 

 apophysis is given off on either side, so as to meet nearly 

 in the middle, where they are united by ligaments and muscles 

 at the chin, which is square, with a fissure in the middle. 



* Swains. Nat. Class, and Geog. Dist. Anim., p. 224. 



