354 HSHES. 



external pterygoid in (No. 24). It has them also at its superior 

 (Nos. 61, 62), and inferior (No. 56),pharyngeans,and at all the tube- 

 rosities of its branchial arches ; but they are absent on the tongue. 



We describe the teeth in reference to their position, according to 

 the bones to which they are attached. Thus we make a distinction 

 between the intermaxillary teeth, maxillary, mandibulary, vomerian, 

 palatine, pterygoidean, lingual, branchial, and the superior and infe- 

 rior pharyngeans. 



Their forms are not less varied than their position, and give rise 

 to epithets still more numerous; most frequently they represent cones, 

 or hooks, more or less sharp ; when these hooks are numerous and 

 disposed in several ranges or in the form of a quincunx, they are com- 

 pared to the points which are presented by cards for carding wool 

 or cotton ; frequently they are so thin and so dense, as to appear to the 

 eye like the pile of velvet, and when they are at the same time very 

 short, and also very dense, they then have the appearance of smooth 

 velvet, but when they are elongated and weak, they form brushes or 

 species of hairs. In short, these little delicate teeth may be at the 

 same time so short, that they are reduced to a simple asperity more 

 capable of being detected by the touch than by the eye. It will not 

 be difficult for any person to comprehend the terms which we employ 

 to describe these various shades of difference. Independently how- 

 ever of these teeth in hooks, there exist also trenchant ones in the 

 form of a wedge, as the anterior ones of the genus sargus and the 

 pharyngeans of the genus scarus. The trenchant maybe dentated as 

 in the genus acanthurus, or they may be sharply pointed in its middle, as 

 in the serra-salmons. There are also round, or hemispherical, or 

 oval, as the posterior teeth in sparrows; these round teeth are disposed 

 in several rows, or compacted together like paving stones, as may be 

 seen in the palate and tongue of glassodenti on the jaAvs of the ray, on 

 the pharyngeans of labrus, and many sciense. Some teeth also are 

 pointed or compressed, and trenchant on two sides, as those in trichi- 

 urus and chirocentrus ; others with their croAvn flax, and raised in 

 salient lines as those of the pharynx of the carp, or which rise in a 

 mass as those of the pharynx of many cyprins. There are some 

 teeth again with tubei'cles on the crown, as those of myletes, &c. 



All these teeth are simple, and are produced likewise from one 

 simple pulpy germ. 



Whatever be the form of the teeth, the growth of the simple ones 

 is always the same, and is accomplished by successive layers, as is the 

 case with the teeth in mammalia ; but the growth does not proceed at 

 any time so far as to form a root which would descend into the socket. 

 The teeth of fishes like those of tlie monitors and many other saurians, 

 consist only of that part called the crown, and when this crown is com- 

 pletely formed, the pulpy nucleus on which it exists becomes ossified ; 

 when the tooth is about to fall, it breaks, and is detached from this 

 ossified nucleus which remains, and being united to the jaw forms a 

 part of it; in some species however, as in those of anarhicas, the osseous 

 nucleus now becom.e larger than the tooth, and forming a prominence 

 on the jaw, is detached exactly as the stag's horns, and probably by 



