92 gangetic fishes. Order IV. 



The bones at the entrance of the throat are also covered with 

 teeth. Both apertures of each nostril are oblong. The eyes 

 are large. The bones of the cheek are indented round the 

 edge, with some of the toothlets at the angle rather long. In 

 each gill-cover are three plates quite entire on the edge j and 

 the posterior one ends in a point. The membrane of each gill- 

 cover is not concealed, and contains seven rays. 



The back is much arched, and has a furrow for receiving the 

 foremost fin. The belly is nearly straight. The edge of the 

 scales is minutely indented. The scales are large, and separate 

 easily. Above the commencement of each lateral line is a 

 scaly space surrounded by an indented margin. Above each 

 ventral fin is a short scale-like appendant. 



The two dorsal fins, although fully united, are easily distin- 

 guishable, each forming an arch. The edge of the first, as in 

 the preceding species, resembles that of a saw. It has strong 

 prickles, all separated by membranes, and the fifth is the long- 

 est. The second fin is scaly at the base, and the first of its 

 rays, all of which are soft, is undivided, and the last is divided 

 to the root into two. The pectoral fins are not so long as the 

 head, and are very sharp above. Each contains seventeen rays, 

 of which the first, second, and seventeenth, are undivided, and 

 the first and last ai'e very short. The ventral fins are near each 

 other, and are rather short. In form they entirely resemble 

 those of the Datnia. The fin behind the vent is arched, its 

 prickles are strong, and the first of its soft rays is undivided. 

 The tail fin ends in a small concavity, and is blunt at both ex- 

 tremities. It has seventeen distinct rays, besides some short 

 compacted ones at each side. 



4th Species. — Coius trivittatus. 

 A coius with the tail fin bifid, with eleven prickles and ten 



