THE FISH. 3 



great number of small articulations, and generally 

 divided into branches at the extremity, are called soft, 

 articulated, or branched rays. 



As to the number of limbs, we may observe as 

 many varieties as among the reptiles. Generally there 

 are four ; some, however, have but two, and others 

 are without them altogether. The bone which repre- 

 sents the scapula is sometimes suspended in the flesh, 

 as in the previous classes ; at other times, it is 

 attached to the spine, but more commonly it is sus- 

 pended to the cranium. The pelvis seldom adheres 

 to the spine, and very often, instead of being behind 

 the abdomen, it is before, and belongs to the humeral 

 apparatus. 



The vertebrae of fish are united by concave sur- 

 faces filled with cartilage, they in general commu- 

 nicate by a canal dug in the axis of the vertebrae ; in 

 the majority they have long spinous processes, which 

 support the vertical form of the body. The ribs are 

 often fastened to the transverse processes. These 

 ribs and processes are commonly known by the name 

 of crests or ridges. 



The head of fishes varies more in form than that of 

 any other class, although it is in general divided into 

 the same number of bones as that of other oviparous 

 animals. The frontal is composed of six pieces : the 

 parietal of three ; the occipital of five ; five of the 

 pieces of the sphenoid and two of those of each of 

 the temporal bones remain in the composition of the 

 cranium. 



b2 



