MUSCULAR SYSTEM OF FISHES. 425 



bone, and the ray which terminates it, to a con- 

 siderable distance. This structure is distinctly 

 seen in the small dorsal fins of the Mackarel. 

 The anal fins, which are situated on the lower 

 side of the body, in the vertical plane, and next 

 to the tail, are, in like manner, supported by 

 rays, having the same parallel, or fan-like arrange- 

 ment as the preceding. The caudal fin, or ter- 

 minal expansion of the tail has also a similar 

 structure. 



The muscles of fishes compose a large portion 

 of the bulk of the body, but they are arranged 

 in a less complex manner than those of the ani- 

 mals of the higher classes. Those which appear 

 immediately underneath the integuments are 

 shown in Fig. 194, where M, M are the great 



N 



lateral muscles, producing the flexion of the 

 body and tail : D is the dorsal fin, which is 

 raised by the muscle d ; p, the pectoral fin, 

 expanded by the muscle p : v, the ventral fin, 

 moved by the muscles situated at v: A, the anal 

 fin, in like manner moved by muscles at its 

 base a : and c, the caudal fin, the muscles for 



