188 gangetic fishes. Order V. 



The first fin of the back slopes backward, with a slightly con- 

 cave edge. The first of its rays is a very short bone. The se- 

 cond is a prickle, smooth on both edges, and terminates in a 

 long point, flexible like whalebone, which extends far beyond 

 the membrane uniting the other six rays, which are branched. 

 The second fin is rather shorter than that behind the vent, and 

 is nearly triangular. The pectoral fins are low, sharp above, and 

 longer than the head. Each has thirteen rays, of which the first 

 is a strong prickle, smooth on both edges, and terminated by 

 a flexible point, that extends far beyond the membrane join- 

 ing the other rays, the two last of which are undivided- The 

 ventral fins are much shorter than the head, and their edge 

 forms a slight concavity. Each has six rays, of which the first 

 is undivided. The three first rays of the fin behind the vent 

 are undivided, and lengthen gradually from the first, which is 

 short. The remaining ten are branched, and their ends form a 

 concave edge. The tail fin is very long, and is divided into two 

 lobes, of which the uppermost is the longest, and bent like a 

 hook. Each ends in a long slender point ; and, in the whole, 

 there are seventeen distinct rays, besides some compacted ones 

 on each side. 



21st Species. — Pimelodus cavia. 



A Pimelodus with the fin of the tail divided into two lobes, 

 the undermost of which is the longest ; with eight tendrils not 

 longer than the head ; with an opaque scabrous clouded body ; 

 with nine rays in the fin behind the vent ; and with five in the 

 foremost of the back fins. 



This fish may possibly be the same with the Pimelodus cous 

 of La Cepede, (Hist, des Poissons, Tome V. p. 110,) for the de- 

 scription given by him is so short, that one cannot be satisfied 

 on the subject. What he states, however, respecting the co- 



