THE HEAD OF A NEW FOSSIL ANIMAL. 473 



is a small, smooth, superficial groove, Pig. <2. //. and on its 

 inner side, a small, smooth, slightly convex, apparently ar- 

 ticulating surface. Fig. 2, t. 



The general figure of the upper maxillary bone will be 

 better understood by ;i view of the drawing. Pig. 1, c. than 

 by any verbal description: this bone is imperfect posteriori)'. 

 Superior and anteriorly, near its junction with the lasl de- 

 scribed hone, the upper maxillary has a smooth, apparently 

 articulating surface, convex antero-posteriorly, and inclining 

 a little inwards, Fig. 2. g. ; like the dental and inter- 

 maxillary bones, this has also distinct alveoli for the teeth: 

 and near it- alveolar margin, on the inner surface, there is 

 a regular series of foramina, similar to those in the dental 

 bone, for the transmission of the superior maxillary nerve 

 and vessels to the teeth. The external surface of this hone 

 and also of the intermaxillary, where not broken, presents a 

 shagreened appearance. 



The teeth in both jaws are placed close together, in a sin- 

 gle row. in distinct alveoli: they are also similar, those in 

 the lower jaw. however, being rather more compressed than 

 those of the upper: the anterior teeth of the lower jaw are 

 smaller than the posterior. The crowns of the teeth are 

 enamelled, smooth. Unciform, slightly inclined inwards : 

 those at the posterior portion of the lower jaw slightlj 

 curved forwards. Their roots are hollow, slightly grooved 

 on their external aspect; on their internal aspect there i- 

 a very slight groove. See section magnified three times, 

 Fig. in. 



Th. young teeth grow into- the hollow of tin old. The 

 mode of dentition is shown in Fig. 5 : /. is the new tooth, m. 

 the old. 



There appear to have been nine or ten teeth in each in- 

 termaxillary, and about thirty in each upper maxillary hone ; 

 wear, unable to ascertain satisfactorily the number of teeth 



in the lower jaw . 



This animal, though it- head bears some resemblance to. 

 evidently does not belong to the great Saurian family, (/,</- 



