192 Mr. J. McClelland on Indian Cyprinidae. 



XXIV. — Indian Cyprinidae. By John McClelland, Assist- 

 ant Surgeon Bengal Medical Service. 



[Continued from p. 121.] 



47. It remains to notice the analogical relations of the 

 Loaches, an exceedingly numerous group in India, many spe- 

 cies of which are common in every pond throughout Bengal 

 and Assam. In these fishes we shall find the characters of 

 rasorial birds as well as quadrupeds so strongly depicted as to 

 leave no doubt of their forming an equivalent type among 

 Cyprinidae. 



When noticing the difference between the true Loaches 

 (Cobitis) and Schisturce, I omitted to mention, that in the dis- 

 sections of five species of the former — all I have had an oppor- 

 tunity of examining — I could find no natatory bladder ; while 

 in the only species of the latter which I have been able to in- 

 spect, I found that organ, though small and peculiar in its 

 form, yet sufficiently developed to lessen considerably the 

 specific gravity ; enabling the Schisturte to swim with facility, 

 though perhaps with less buoyancy and ease than other Cy- 

 prinidce*. But if a natatory bladder exists at all in the true 

 Loaches (Cobitis prop.), or those whose caudal is entire, it 

 must be in the manner described by Schneider, very small, 

 and inclosed in a bony bilobate case which adheres to the 

 third and fourth vertebrae ; but even in this rudimental shape 

 I have been unable to find an air-vessel in any Indian spe- 

 cies yet examinedf. 



This peculiarity, together with their small and weak fins, 

 as well as lengthened and cylindric form, approaching to that 

 of the Murcenida, afford satisfactory evidence that they are 

 less adapted for swimming than any other Cyprinidae, and 

 may therefore be said to be more terrestrial in their habits, 



* Schistura dario and geta have a membranous air-vessel placed in the 

 upper part of the abdomen, as in ordinary Cyprins, but it consists only of a 

 single lobe. S. dario, Buch., is the only species of the Linnaean genus 

 which I have found to frequent deep waters in the open channels of the 

 Ganges and Bramaputra. 



f Since this was written, I have found the air-vessel in all these species 

 situated in a small bony case immediately over the entrance of the oesopha- 

 gus from the mouth. Plate 56, fig. 5, is a magnified representation of the 

 organ (which is not larger than the head of a pin) as it occurs in Cobitis 

 guntea, Buch., and other neighbouring species of the same subgenus. Fig. 4, 

 plate 56, represents the same organ in several of the smaller Schisturce, in 

 which it is also placed over the entrance of the oesophagus, and in both cases 

 probably answers the purpose of the branchial or pharyngeal teeth in the 

 Pceonomince, especially as the external surface of the bony crust which sur- 

 rounds the air-vessel is, as represented in the figures, studded with minute 

 spines. 



