TEETH OF FISHES. 



373 



be cited, besides the nasal teeth of the Lepidosiren, fig. 251, c, 

 and the occipital alveolus of the Carp and Tench, fig. 250, the 

 marginal alveoli of the prolonged, depressed, well ossified rostrum 

 of the Saw-fish (Pristis, fig. 65). In the Lampreys, fig. 138, and 

 in Helostomus (an osseous fish), most of the teeth are attached to 

 the lips. Lastly, it is peculiar to the class Pisces, amongst Verte- 

 brates, to offer examples 

 of teeth developed in the 

 median line of the mouth, 

 as in the palate of the 

 Myxines, fig. 248, a; 

 or crossing the symphy- 

 sis of the jaw, as in 

 Notidamis, Scymnus, and 

 Myliobates, fig. 249. 



Nor is the mode less 

 varied than the place of 

 attachment. The teeth 

 of Lophius, Pcecilia, 

 Anableps, are always 

 moveable. In most 

 fishes they are anchy- 

 losed to the jaws by con- 

 tinuous ossification from 

 the base of the dental 

 pulp. Sometimes we 

 find, not the base, but 

 one side, of the tooth anchylosed to the alveolar border of the 



Beak of Parrot-flsh {Seams mnricatus). v. 



259 



Seel ton of the jaw of the Parrot-fish, showing the progress of dentition, v. 



jaw ; and the teeth oppose each other by their sides instead 



