Squalus. gangetic fishes. 3 



membrane arising from the fore part of the head, and ending 

 behind in a semicircular sinus. Under the fore part of this 

 membrane, at each side, is a large aperture in form of a cres- 

 cent, probably a nostril. In both jaws there are various rows 

 of blunt teeth, closely wedged together. The apertures for 

 breathing consist of five slits placed behind each angle of the 

 mouth, so as with it to form a kind of circle open towards the 

 tail. 



The body every where below, and towards the sides above, 

 is quite smooth ; but on the middle of the back is covered with 

 small rough scales, The vent is behind the middle. The tail is 

 more than twice the length of the whole body, and very slen- 

 der. It is quite smooth, and tapers gradually from the root, 

 which is flat, to the point, where it becomes like a thick 

 thread. It is scabrous above ; but is neither prickly nor armed 

 with a spine. 



There is no dorsal fin, but behind the head there is a light 

 coloured hard protuberance, the rudiment probably of this or- 

 gan. The pectoral fins edge the greater part of the body, and, 

 forming a slight angle near the middle, are rounded behind. 

 The ventral fins are much smaller than the pectorals, and edge 

 the body between them and the tail. They are rounded be- 

 hind, and their edges are indented. On the under side of the 

 tail is placed a narrow^ without rays. It commences about 

 three quarters the length of the body from the root, and runs 

 along for about a space equal in length to the body. 



II. Genus. — Squalus or Shark. 



Fishes of the first order having on each side of the neck from 

 five to seven breathing apertures, without gill-covers or mem- 

 branes. 



In the mouths of the Ganges sharks are exceedingly nume- 



