342 



S A U R I A. 



DESCR. The head is very much depressed, declivous from the occi- 

 put to the snout, hence, wedge-shaped in its general appearance ; seen 

 from above, its outline is subovoid. The cephalic plates, polygonal as 

 usual, smooth or subnodulous, are proportionally well developed. The 

 frontals are the most conspicuous; they are symmetrically arranged in 

 three pairs, the middle pair of which is the largest, inclosing two cen- 

 tral odd plates upon the vertex. The vertex plate proper, however, 

 does not come into contact with the latter, since the posterior frontals 

 are contiguous upon their inner margin. Three occipitals constitute 

 another conspicuous group, though more angular each than the fron- 

 tals ; the occipital pit is not conspicuous, but may be detected, as usual, 

 upon the middle of the central plate. The group just alluded to is 

 surrounded by a chain of smaller plates. Two or tln'ee supraoculars 

 are considerably larger than the rest, the smallest of which constitute 

 a subconcentric series, along the occipital, vertico-frontal, and supra- 

 ciliary lines. Others, equally small, occupy the anterior external 

 third of the supraocular region, either irregularly disposed, or arranged 

 upon three oblique series. There are two pairs of fronto-nasals : the 

 anterior pair being the smallest, subquadrangular, and in contact with 

 the rostral ; the posterior pair is subquadrangular also. We likewise 

 observe two minute interfronto-nasals. The nasal, situated upon the 

 prolongation of the supraciliary ridge, is pyriform; its narrowest extre- 

 mity coming into contact with the rostral. The nostril is large and 

 circular, situated near to its posterior margin. The rostral is trans- 

 versely elongated, very low, and slightly convex upon its upper edge. 

 We observe five elongated upper labials, largest upon the middle of 

 the series. There is but one row of elongated and very exiguous 

 supralabials, about five in number. Three angular and small plates 

 occupy the loral region. There are but two suborbitals, a posterior, 

 very small, scale-like, and a very elongated one, forming almost exclu- 

 sively the inferior rim of the orbit. The surface of the eyelid is granu- 

 lar ; its margin exhibits a double row of subquadrate, small plates. 

 The temporal scales are well developed, and subcarinated or smooth. 

 The symphyseal is very large, rounded upon its maxillary edge, other- 

 wise angular. The lower labials are broader than the upper ones, but 

 not quite so long : the fifth is very small ; the succeeding ones can 

 hardly be distinguished from the adjoining scales covering the throat, 

 two series of which may be observed between the labials and the men- 

 tal shields. The latter are quite developed, constituting four diverg- 



