2 SHARKS AND RAY-FISHES. 



system of nature, although professedly artificial, was intimately 

 connected with a profound knowledge of the affinities of natural 

 objects, has even gone so far as to separate them essentially from 

 the great family of true fishes, by making them a branch of his 

 class of amphibious animals, under the title of swimming amphi- 

 bians: the serpents and other reptiles being formed into another 

 class of the same general order. 



CHONDROPTERYGIOUS FISHES. 



Having a skeleton with few bony particles in its structure, and also 

 termed Plagiostomi from the situation of the mouth, and it may be 

 added, the nostrils, which are beneath a projecting snout. 



SHARKS AND RAY-FISHES. 



As regards their proper station in the natural classification of 

 animals we so far agree with the distinguished Swedish naturalist 

 Linnreus, as to place the family which comprises the Sharks and 

 Rays in the rank which is next below that of rej)tiles; to which 

 order they are most nearly related in their general structure, 

 vital physiology, and mental instincts; and not in the much 

 inferior station which includes the Lampreys, as is done in the 

 great part of modern arrangements. 



With the Lampreys, myxinc and lancelet, this class of fishes 

 possesses nothing in common, except a soft skeleton that for the 

 most part is without bony fibres, and several openings through 

 which the water passes in the action of breathing; which are 

 agreements too slight and obscure to warrant the conclusion that 

 these families possess any near connection of natural affinity; 

 whereas the differences in other respects, and even in the par- 

 ticulars named, are very wide, as we shall presently see. And 

 therefore, while we suffer the last-named family — of Petromy- 

 zonidce, or Lampreys, to remain at the end of our list, as at the 

 vanishing point of fishes in their transition towards the class 

 of worms, we assert for this tribe of chondrojJterygious fishes 

 a prominent station at the head of the whole family of fishes. 



It is because of the softness of the skeleton in the class of 

 chondroptcrygious fishes that the minds of naturalists have been 



