18 



RIBAND-SHAPED. 



bones of the dorsal rays become apparent on the surface of 

 the thin external covering. 



The head from the end of tlie nose to the posterior margin 

 of the gill-cover is contained seven times and a quarter in the 

 total length ; the length of the head is therefore nearly equal 

 to the height of the fish at the nuchal region. The outline 

 of the lower jaw forms an ascending arch, which at the angle 

 of the mouth meets the straight and slightly declining profile 

 of the forehead, by which the lower jaw, Avhen the mouth is 

 closed, becomes much elevated, and the opening of the mouth 

 turned upwards. When the lower jaw sinks into a horizontal 

 position, the upper jaw is much projected, and becomes some- 

 what longer than the lower. 



The fonnation of the jaws, the form and position of the 

 gill-covers, and the radiating grooves on the latter, on the 

 jaws and frontal bones, agree with the description of those 

 parts in the Tr. Falx, as given by M. Valenciennes, to which 

 I beg to refer as far as regards the Vaagmaer. 



