300 FISHES. 



moveable. Sometimes even, these articular svirfaces exist on one side 

 of the vertebrae and not on the other, so that they have nothing to 

 articulate with. The annular portion of the first vertebrae is very 

 often distinct from its body during the entire life of the first. In the 

 others, they are either not sejjarated, or they soon become conjoined. 



In some fishes, as the muren, a part of the anterior vertebrae is 

 distinguished beloAv the body, by a little crest or vertical apophyse. 

 In several also, the bodies of part of the vertebrae are soldered to- 

 gether ; examples of this will be found in the cyprins, the silures, 

 and the fistulaira, and instances still more strongly marked in many 

 of the chondropterygians, 



The vertebrae placed over tlie cavity of the abdomen (No. 67, 67) 

 have transverse apophyses more or less strongly marked, which re- 

 main a long time, distinguished by sutures, and easy to be separated 

 from the body of the vertebrae, as in the cyprins. In certain fishes, 

 the hake, for instance, these transverse apophyses are very large, 

 and give attachment to the natatory bladder. At one time the ribs 

 are suspended by these apophyses ; at another they are fixed behind 

 them to the body of the vertebrae. In this respect there is a great 

 variety. 



In the vertebrae, of the back part of the abdomen (Nos. 68, 68) 

 the tranverse apophyses are in general prolonged, and directed down- 

 wards ; the last of them are often united with each other by a 

 transverse, thus forming a ring. There are some of these inferior 

 rings running the whole length beneath the vertebra of the tail 

 (Nos. 69, 69,) where they form a canal for the lodgment of the 

 trunks of the vessels, in the same way, that the superior canal lodges 

 the medullary cord. Besides these, there are in many fishes other 

 transverse apophyses on the sides of the tail. 



From these inferior rings of the tail, spinous apophyses arise (b. h.) ; 

 but these are directed downwards, as those of the superior annular 

 part are directed upwards, so that the vertebrae appears nearly the 

 same in the two directions. 



The inferior rings, like the superior often have a sort of articular 

 apophyses, which are even sometimes large, and branched, thus form- 

 ing round the vascular canal a kind of net work. This particularity 

 is observed in certain species of the genus Tunny. 



The vertebrae which approach the end of the tail, have their 

 apophyses gradually shortened, their canal is narrowed, or closed ; 

 the last unite their apophyses together, and with the last interspinal 

 small bones, thus forming with the last of all a triangular vertical 

 plate (No. 70), to the posterior border of which are articulated the 

 rays of the caudal fin (No. 71)- Fishes that have long and 

 pointed tails however, have not this disposition constantly ; for in- 

 stance, it does not exist in the eel ; in others, such as the pike, this 

 form still prevails. 



The number of vertebrae, their relative length, breath, and height, 

 their furrows or fossettes that mark their bodies, the height and 

 direction of their apophyses vary to infinity, and even frequently 

 differ in a remarkable manner, in different parts of the same spine ; but 

 these details can only be glanced at till we come to describe species ; we 



