M 



'.'.' The premandibular and premaxillary bones of a large fish of the geium 

 Cottypkiu. Htmterian. 



98. The premaxillary and prcmandibular bones of a large fish of the genii* 

 CoMgpkiu. There are two large laniariform teeth at the fore-part of each prv- 

 inuxillary . and one such tooth at the fore-part of the premandibular lx>nc : H 

 few small conical teeth represent the rest of each series, which is not ter- 

 minated by any larger laniary. The inner side of the alveolar border of the 

 jaw is paved by a broad band of small tubercular teeth. 



Presented by William Lynn, 



94. The superior and inferior pharyngcal bones of a Labroid fish. Huntcrian. 



95. The two superior pharyngcal bones of a Labroid fish, with their pavement of 



molar teeth. 



The whole of the unattached surface of the pharyngeals is covered with these teeth, which 

 vary in sue and shape in different parts of the pharyngeal bone* ; many are round, some are 

 angular, and some of the smaller ones at the external angles present a conical form. Each 

 tooth is attached by the circumference of a slightly contracted base to the margin of a shallow 

 alveolus ; this margin is indented by fine rcrtical grooves, the plates between which are mor- 

 ticed into corresponding grooves in the osseous margin of the base of the tooth. The floor of 

 the alveolus is a thin plate, perforated by numerous foramina, and does not become anchy- 

 losed to the base of the tooth ; nor indeed does it sustain any of the superincumbent pressure. 

 The pharyngeal tooth, when first in place, has its base excavated by a wide but shallow pulp- 

 cavity. This is gradually diminished by a formation of dentine from the margins of the 

 base, which encroaches towards the centre, until it finally forms a partition between the 

 pulp-cavity and the alveolus. In most of the specimens of the pharyngeal bones of the Wrasse- 

 tribe some of the alveoli are empty, and the crown of a new tooth is seen protruding for a 

 greater or less extent through the cribriform base. 



Miu. Brit. 



96. The two superior pharyngeal bones of a large Labroid fish. Hunteria*. 



97. The two superior pharyngeal bones of a large Labroid fish. HutUerian. 

 US. The two superior pharyngeal bones of a large Labroid fish. Mtu. Brit. 



99. One of the pharyngeal bones with its pavement of large obtuse teeth of a Labnu. 

 Two of the cavities of reserve are exposed which contain the germs of succea- 

 sional teeth. llunteria*. 



