100 CARTILAGINOUS FISHES. Class IV. 



Div. II. 



CARTILAGINOUS FISHES. 



J- HIS title is given to all fishes whose muscles 

 are supported by cartilages instead of bones, 

 and comprehends the same genera to which 

 LinncBus has given the name of amphibia 

 nantes : but the word amphibia ought properly 

 to be confined to such animals who inhabit both 

 elements, and can live without any inconveni- 

 ence for a considerable time, either on land 

 or under water; such as tortoises, frogs, and 

 several species of lizards ; and among the qua- 

 drupeds, hippopotami, seals, &c. &c. This 

 definition therefore excludes all that form this 

 division. 



Many of the cartilaginous fishes are vivi- 

 parous, being excluded from an egg, which is 

 hatched within them.* The egg consists of 



* There is evident proof that the Picked Shark, and probably 

 the White, the Basking, and many others, are oviviviparous, or 

 hatch the young within them, whilst the Spotted shark deposits 

 its purse or egg in the same manner as the Ray tribe. In the 

 Philosophical Transactions of 1810, part 2. p. 205. is a most in- 



