FISHES OF THE BRITISH ISLANDS. 



MAILED CHEEKS. 



Cuvier says of this family of fishes, that it contains a 

 numerous class to which the remarkable appearance of the 

 head, variously armed and protected, gives a peculiar aspect 

 which has always caused them to be arranged in special genera, 

 although they have many close affinities with the family of 

 Perches. Their common character consists in having the bone 

 beneath the orbit more or less extended over the cheek, and 

 articulated beneath with the first bone of the gill-cover. The 

 teeth generally are fine. The pectoral fins in the whole of 

 this class receive an extensive development, and are prepared 

 for functions somewhat different from those exercised by the 

 greater number of fishes; the separate rays of those fins being- 

 endowed with special powers of sensation, for the exercise of 

 which they are supplied with nerves of more than ordinary 

 size. The bones at the setting on of those fins are so arranged 

 as to constitute what may be termed an arm, and the branches 

 of the nerves pass along these bones, to proceed through an 

 opening formed for that purpose between two of the bones, 

 which may be called by the corresponding terms in the anatomy 

 of man, the radius and ulna. The formation of the joints of 

 these fins enables them to exercise extensive motion; and as in 

 their more natural position, they are laid flat on the sides of 

 the fish with a direction backward, those rays become the 

 lowest which are most disengaged from their connection with 

 others, and so answer more nearly to the human thumb and 

 VOL. II. B 



