118 Mr. J. M'Clelland on Indian Cyprinidae. 



presence or absence of a spinous ray are scarcely sufficient 

 distinctions even for a subgenus ; and the Catastomi and La- 

 beos of America will, I presume, be found to arrange them- 

 selves naturally with the Cin-hins. 



The lower jaw of the Gonorhynchs is composed of two 

 limbs placed nearly parallel to each other, and, as in the Cir- 

 rhins, not united in front, but with this peculiarity, that the os 

 hyoides is prolonged to the chin, at which situation the ante- 

 rior extremities of the three bones are tied together with li- 

 gaments*. 



In the Opsarions, and generally throughout the Sarcobo- 

 rince, the second form of jaw prevails, with the addition of 

 being more acute at the symphysis ; this form also seems to 

 prevail in the Cobitiiue, but in these the bones of the jaw are 

 soft and flexible. The limbs of this organ are round and slender 

 in Cobitis prop., but firmly united in front by means of two 

 expanded apophyses ; while in Schistura they are flat and ob- 

 liquely inclined to each other, so as to form, by means of their 

 inner edges, a lengthened symphysis, 



43. Thus we appear to have three primary types : the first 

 distinguishes the Cirrhins, Labeos, and probably Catastoms ; 

 a second is peculiar to the Barbels, Opsarions, and numerous 

 other genera ; and a third is seen in the Gudgeons. From 

 these three types being so prominently developed in the Pceo- 

 nom'mee, while one principle chiefly seems to run through all 

 the Sarcoborincs, it is perfectly legitimate to conclude, even 

 from this circumstance alone, that the former should be the 

 most perfect group of the two, and that its species should con- 

 sequently be endowed with more diversified instincts; hence, 

 although a vegetable regimen is the great characteristic of the 

 Pceonomince, still many of the species are omnivorous, and this 

 is to be expected, especially among the Cirrhins and the true 

 Carps {Cyprinus prop., Cuv.). The Barbels, however, as well 

 perhaps as the Breams, which appear to be peculiar to Europe, 

 seem to partake more of carnivorous habits, and therefore 

 must be held as the subtypical, while the Cirrhins are the ty- 

 pical t ; and the Gudgeons and Gonorhynchs, from their pos- 

 sessing in the greatest perfection the single instinct for a ten- 

 dency to which the Pceonomince are most remarkable, viz. sub- 

 sisting exclusively on a vegetable regimen, are as unques- 

 tionably the aberrant forms of Paonotiiina : on the other hand, 

 the rapacious habits of the SarcoboriruB mark them so con- 



* Vide Journ. As. Soc. Beiig., 1835, p. 40, where I described this struc- 

 ture iu Gonorliynchus jyetrophilus. 



\ The Cirrhins being the most perfect forms of a typical group, are 

 strictly, in llic language of JMr. Swaimon, pre-eminently typical. 



