FISHES. 1 1 



Herring and Pilchard for example, have similar 

 thread-like branches sent oft from each of the 

 vertehrce ; so that the bodies of these fishes seem 

 filled with long and slender bones. 



The skull varies much in form in different 

 tribes, but in general consists of pieces answering 

 to those which compose the head of the other 

 Vertebrata. Teeth are generally very numer- 

 ous ; and are found in almost every one of the 

 bones that enter into the composition of the 

 mouth, though not in all the species. They are 

 generally simple spines, curved backwards, but 

 innumerable modifications of this form occur. 

 Thus the jaws of the deadly Shark are flat and 

 lancet-like, the cutting edges being notched like 

 a sau ; the front teeth of the Flounder are com- 

 pressed plates ; some, as the Wrasse, have flat 

 grinding teeth ; others, as the Sheep's-head, have 

 the grinding surface convex ; and others, as the 

 genus Chrysophrys, have convex teeth so numer- 

 ous and so closely packed over a broad surface, 

 as to resemble the paving-stones of a street. The 

 beautiful Chaetodons oi' warm climates, on the 

 other hand, have teeth which resemble bristles, 

 and these are set close together like the hairs of 

 a brush ; while the Perch of our own rivers have 

 them still more slender, minute and numerous, 

 so as to resemble the pile of velvet. Another of 

 our well-known fishes, the bold and fierce Pike, 

 is armed with teeth scarcely less formidable in 

 size, form, and sharpness, than the canines of 

 a carnivorous quadruped. In number also there 

 is great variety. The Pike, the Perch, the Cat- 

 fish, and many others, have their mouth crowded 

 with innumerable teeth, while the Carp and the 



