INDIAN CYPRINID. 249 
bladder, while in the only species of the latter which I have been able 
to inspect I found that organ, though small and peculiar in its form, yet 
sufficiently developed to lessen considerably the specific gravity, enabling the 
Schisture to swim with facility, though perhaps with less buoyancy and 
ease than other Cyprinide.* 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 enclosed in a bony bilobate 
case which adheres to the third and fourth vertebra, but even in this 
rudimental shape I have been unable to find an air vessel in any Indian 
species yet examined.+ 
This peculiarity, together with their small and weak fins, as well as 
lengthened and cylindric form, approaching to that of the Murenide, 
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, living chiefly on sandy and muddy bottoms, or in jeels amidst 
aquatic vegetation. 
* 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. darz%o, Buch. is the 
only species of the Linnean genus which I have found to frequent deep waters in the open channels 
of the Ganges and Bramaputra. 
+ 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 cesophagus from the mouth. Plate 56. f. 5, is a magnified 
representation of the organ (which is not larger than the head of a pin) as it oceurs in Cob?¢is 
guntea, Buch. and other neighbouring species of the same sub-genus. Fig. 4, Plate 56, represents the 
same organ in several of the smaller Schéstwx@, in which it is also placed over the entrance of the 
cesophagus, and in both cases probably answers the purpose of the branchial or pharyngeal teeth in 
the Peonomine, especially as the external surface of the bony crust which surrounds the air- 
vessel is; as represented in the figures, studded with minute spines. 
K 
