110 COMMON FLYIXG-FISH. 



lieve, is the conclusion to which he arrives. From 

 fifty to one hundred yards is sometimes passed over 

 by tliis leap or skim, rising considerably above the 

 water, and performing in the leap an arc of a 

 circle. 



In the rays or skates, and some allied genera of 

 cartilaginous fishes, the parts analogous to the pec- 

 toral fins are also much developed, but they are 

 used more as a vast flapper to raise the fish from 

 the bottom, or to bury it in the sand or mud, than 

 as a powerful locomotive organ ; this will be bet- 

 ter understood by referring to Plate Y. page 94. 

 They are not, except that their outline is more 

 angular, very unlike the flat osseous fishes — for 

 example, the flounder C Pleiironectes maximus); 

 but nothing can be more dissimilar in their struc- 

 ture and general economy. When we look upon 

 the flat part of the latter we see the animal in 

 profile, and the exti-eme boundaries of the body, 

 between the snout and tail, ai-e formed by the back 

 and belly, the dorsal and anal fins. On the other 

 hand, when we look upon the flat part of the 

 former, it is either the back or belly that we con- 

 template; and the outline of the body, between 

 the snout and tail, is formed partly by the two 

 ventral, but chiefly by the two pectoral fins. These 

 are attached by an enormous scapular arch running 

 do^vn each side of the simple fin of the animal, and 

 supporting the proper bones of the arm, from which 

 proceed innumerable jointed rays, or fingers, com 

 posed, like all other parts of the skeleton of carti 



