JAWS or FISHES. 1 15 



various shapes, though usually sharp at the points; 

 and either conical or hooked at the extremity, with 

 the points always directed backwards, in order to 

 prevent the escape of the animal which has been 

 seized. Fishes which subsist on testaceous mol- 

 lusca have teeth with grinding surfaces, and their 

 jaws are also adapted for mastication. Every part 

 of the mouth, tongue, and even throat, may afford 

 lodgement for teeth in this class of animals. Almost 

 the whole cavity of the mouth of the Anarrhichas 

 lupus, or wolf-fish, may be said to be paved with 

 teeth, a triple row being implanted on each side ; 

 so that this fish exerts great power in breaking 

 shells. The S/iark has numerous rows of sharp 

 teeth, with serrated margins : these at first sight 

 appear to be formidable instruments ; but as the 

 teeth in the opposite jaws do not meet, it is evident 

 that they are not intended for cutting, like the 

 incisors of mammalia. 



Among Reptiles, we find the Batrachia almost 

 wholly destitute of teeth. Frogs, indeed, exhibit 

 two rows of very fine points; the one in the upper 

 jaw, and the other passing transversely across the 

 palate : they may be considered as teeth existing in 

 a rudimental state; for whatever may be their uses, 

 they are not sufficiently developed to be useful in 

 mastication. There are about forty of these minute 

 teeth on each side in the frog. In the Salamander, 

 there are sixty above and below ; and also thirty on 

 each side of the palate. 



The tongue of the frog is of great length ; its 

 root is attached close to the fore part of the lower 

 jaw, while its point, which is cloven, is turned 

 backwards extending into the throat, and acting 



