462 
TUBE-BLADDERED GROUP. 
By this name may be distinguished a small genus, containing 
seven species, from Continental Europe and Western Asia, and 
differing from the two foregoing by the margin of the lower jaw forming a cutting 
edge, overlain with a brown horny layer; one of the species (Chondrostoma nasus) 
being represented in the lower figure of the illustration on p. 465. These fishes 
are further characterised by the medium or small size of the scales, the termination 
of the lateral line in the middle of the deepest part of the tail, by the dorsal fin 
having not more than nine branched rays, and being situated opposite the root 
of the pelvics, and also by the rather elongate anal bearing ten or more rays. 
The mouth is inferior in position, and transverse; and there are no barbels. 
Commonly known in France as le nez, the figured species does not usually exceed 
18 inches in length, with a weight of about 3 lbs. It is generally found in deep 
water, where it feeds on various vegetable substances, but more especially on the 
green confervoid growth covering submerged stones, which is neatly mown off* 
by a scythe-like action of the horny margin of the transverse lower lip. 
The small roach-like fish known as the bitterlino- (Rhodens 
Bitterlmg. 0 v 
amarus), of which two examples are shown on the left side of the 
accompanying illustration, is the European representative of four genera of small 
