94 SPAROIDS. 



arranged, in the young specimens, in four rows, and all present the 

 hemispherical form. When the individuals have attained seven or 

 eight inches in length, the third row presents three teeth of con- 

 spicuously larger size. In a Gilt-head of eleven inches in length, 

 the molar teeth of the upper jaw are in five rows, and the fourth 

 row presents three teeth larger than the rest, of a sub-elhptic form, 

 with the long diameter transverse ; the large elliptic molars of the 

 adult, of which the long diameter is in the axis of the body, is now 

 formed, but is still concealed in the substance of the jaw. When it 

 has come into place, the mature dentition may be said to be com- 

 plete. The base of the fully formed teeth in use is anchylosed, but 

 in a slighter degree than usual, to a thin osseous lamella, which forms 

 the floor of a shallow depression or alveolus in which the base is 

 lodged. The flat lamella is perforated by numerous foramina, and 

 the sides of the alveolar depression are grooved with numerous 

 radiating lines. 



The texture of both the pointed and obtuse teeth is extremely 

 dense •, it consists of a body of hard white dentine, and a coat 

 of organized enamel, analogous to that of the incisors of the file- 

 fish. The crowns of the rounded molars of the gilt-head hardly 

 suffer the saw to make an impression upon them. Their calcigerous 

 tubes are very numerous and extremely minute, and cross each other 

 towards the periphery of the tooth at acute angles, as in the molars 

 of Lepidotus. The microscopic structure of the anterior pointed 

 teeth resembles that of the incisors of the Sargus, which will be 

 described in the next section. 



38. Sargus. — Fishes which present so close a correspondence in 

 their general conformation and zoological characters as to be included 

 by Linnaeus in the same genus, and by Cuvier in the same natural 

 family, may, nevertheless, differ widely in their habits and be 

 nourished by the most opposite kinds of food, and these peculiarities 

 will be associated with modifications of the digestive system, and 

 especially of the teeth. Of this we have a striking example in the 

 Bream-tribe. In the Dentex (the Sparus dentex of Linnaeus), the 

 dentition was of a predatory and destructive character, all the teeth 

 being formed to seize, and pierce, and lacerate. In the Chrysophrys 



