XYIU INTUODUCTION. 



opinion of the best Iclitliyologists, tliey are second only to 

 the fins ; which, in their number, situation, size, and form, 

 are admitted to be of first-rate importance. Some fishes 

 have teeth attached to all the bones that assist in forming 

 the cavity of the mouth and pharynx ; to the intermaxillary, 

 maxillary, and palatine bones, the vomer, the tongue, the 

 branchial arches supporting the gills, and the pharyngeal 

 bones. Sometimes the teeth are uniform in shape on the 

 various bones ; at others differing. One or more of these 

 bones are sometimes without teeth of any sort ; and there 

 are fishes that have no teeth whatever on any of them. The 

 teeth are named according to the bone upon which they are 

 placed ; and are referred to as intermaxillary, maxillary, pala- 

 tine, vomerine, &;c. — depending upon their position. 



A reference to page 3 in the second volume will show the 

 situation of the teeth in the Trout, with five rows on the 

 upper surface of the mouth, and four rows below ; the parti- 

 cular bones upon which these rows fire placed are also referred 

 to. The form of the teeth in fishes is various ; in general it 

 represents that of an elongated cone, slightly curved inwards 

 to assist in holding a prey which is frequently alive. Some- 

 times the form is that of a short and rounded tubercle, adapt- 

 ed for crushing ; iii some fishes the teeth are so small and 

 numerous as to have the appearance of the hairs of a brush ; 

 while in others they are thin and flat, with a cutting edge 

 like the incisor teeth in the human subject. Some fishes 

 that are without teeth in the mouth, have them in the 

 throat ; this is particularly the case in the Carp, and the 

 allied species in the family of the Cyprinida generally. In 

 this family the pharynx is provided with five pair of branchial 

 arches, the four most anterior of which support the four rows 

 of gills ; the fifth pair, remarkable for the strength of the 

 bone, support powerful teeth. The woodcut here introduced 



