280 SUPPLEMENT ON 



paration from the Linntean genus trigla, are noticed in their 

 proper place ; and we shall not refer to them here, except to 

 observe that the pectoral fins, by means of which they make 

 their aerial excursions, are as long or longer than the body, 

 and are supported by articulated rays, something like those 

 of the wing of a bat. It is by this extension of the pectoral 

 rays and membrane that the fish is enabled to raise itself from 

 its proper element to the regions of air, though this is by no 

 means a continued flight, for the utmost it can do is to describe 

 an arch over the surface of the water extending to a distance 

 of about 120 feet, and sufficiently elevated for the fish some- 

 times to fall on the deck of a large vessel. This power of 

 flight or momentary suspension would be much greater if the 

 pectoral membrane could preserve its humidity longer ; this 

 is soon evaporated in the heat of the tropics, and the mem- 

 brane, as it becomes dry, loses its buoyant power, and the 

 fish falls. 



These fish are sometimes so numerous as to afford much 

 pleasure to the spectator by their repeated flights, and at par- 

 ticular times, especially on the approach of rough weather in 

 the night, numbers of them may be seen, by the phosphoric 

 light they emit, marking their arched passages in apparent 

 streams of fire. It is not, however, for their own pleasure or 

 amusement that they thus quit their natural element. But few 

 animals seem to be more beset by enemies than the flying 

 fish : pursued by many fish, especially those of the genera 

 coryphaena and scomber, they seek refuge in their temporary 

 flight; but if they thus escape these enemies, they frequently 

 fall a victim to the sea birds, which are hovering over to 

 pounce upon them. 



They feed on mollusca, naked and shelled, and on Crus- 

 tacea, whose covering they break by means of their obtuse 

 teeth. They are eaten, but are not much esteemed. 



The cotti, C. Gobio, the miller's thumb, or river bullhead, 



