86 COMPARATIVE DENTAL ANATOMY 



produced in countless numbers, as in the Salmon 

 and Pike, or may be reduced to only one tooth, as 

 in the Myxine, or there may be none at all. 

 There is no general rule as to the number, posi- 

 tion, or form in this great class. They are very 

 general in form and undifferentiated, and may 

 vary extensively even among the individuals of 

 the same species. 



Forms and Function. The teeth of fishes are 

 derived from the simple cone, by various modi- 

 fications. The conical teeth present great vari- 

 ety, — from long, fine, hair-like forms, to short, 

 stout cylinders, and in others they may vary from 

 cone to cylinder, from cylinder to plate. The 

 teeth of fishes are designed for prehensile pur- 

 poses mainly, as there are no masticating teeth 

 proper in this class, though some species have 

 pavement-like teeth, for crushing purposes. The 

 conical teeth are often fine or hair-like; or so 

 short as to be only felt with the fingers; or long 

 and slender; or long and strong; or stout and 

 short, — such teeth being attenuated cones in 

 shape. The cone may merge into the cylinder, 

 this into the compressed triangular form (as in 

 the Shark), or stout with rounded summits (as 

 in the Wolf -fish), or flattened plates (as in the 

 Eay) or incisor-like form (as in the Sargus). 

 The arrangement is very general and indefinite. 



Structure. The teeth of fishes are generally 



