86 gangetic fishes. Order IV* 



and are of a good size. The gill-covers move freely, and leave 

 large openings. 



The lateral lines are high, and arched in a line parallel with 

 the back. 



In the species that are well defined, although the two fins of 

 the bach, strictly speaking, are united into one, they may be 

 readily distinguished, by the second being higher than the first, 

 and it is shorter, occupying only the sudden slope of the tail, 

 while it consists of soft rays, and those of the first fin are 

 prickles. In some species, however, the back fins resemble 

 those of the Pamas, being more distinct ; but the second, in 

 proportion to the first, is always shorter than in that genus. 

 The pectoral fins are low. Each ventral fin contains six rays, of 

 which the first is a prickle, and the others are branched. The 

 fin behind the vent contains some prickles, separated by mem- 

 branes, and generally more numerous soft branched rays. In 

 several species, both back and anal fins are capable of being re- 

 ceived in a furrow, lined on each side with scales ; and the 

 edges of the hinder fin of the back, and of that behind the 

 vent, owing to their being placed on the slopes of the tail, are 

 nearly vertical. 



As I ended the last genus with some ill-defined species, ap- 

 proaching somewhat to this, so I shall commence the account 

 of this genus with some species that resemble the Bolas. 



1st Species.' — Coius vacti. Plate XVI. Fig. 28. 



A Coius with the tail fin shaped like a fan, with two back fins 

 nearly distinct, the first containing seven prickles, and the se- 

 cond one prickle and eleven soft rays ; and with three prickles 

 and eight soft rays in the fin behind the vent. 



This fish, by the vulgar English of Calcutta, is called Cockup, 

 and is one of the lightest and most esteemed foods brought 



