378 SAURIA. 



conical and tapering posteriorly, not crested, covered with subver- 

 ticillated and keeled scales. 



Syn. —Sceloporus, Wtegm. in 0/cen, Isis, XXI, 1828, 369 ; &, Herp. Mex. i, 1834, 

 18 & 48.— FiTZ. Syst. Kept. I, 1843, 75.— Gray, Catal. Lizz. Brit. Mus. 1845, 209.— 

 B. & G. in Marcj/'s Expl. Bed Riv. of La. 1853, 236. 



Tropidolepis (in part), Cuv. R^gn. Anim. 2d ed. 11, 1829, 38. — Gray, Synops. 

 Kept, in Griff. Anim. Kingd. IX, 1831, 42 ; &, Catal. Lizz. Brit. Mus. 1845, 180 & 

 208.— DuM. & BiBR. Erpet. gen. IV, 1837, 294.— Holer. N. Amer. Herp. II, 1842, 73. 

 — DuM. & A. DuM. Catal. meth. Kept. Mus. d'hist. nat. i, 1851, 76. 



Observ. — This genus, a very natural one in its family, may be 

 distinguished from ProctotretuSy and congeners, by the absence of pala- 

 tine teeth, and of preanal pores also; by the presence of femoral pores, 

 and a fold of the skin, obliquely situated on the sides of the neck, over- 

 lying a well-marked concavity. 



The head is short, depressed, subtriangular in its outline, and 

 obtusely rounded upon the snout. The most conspicuous of the 

 cephalic plates are an odd occipital, a vertex plate, some frontals, and 

 a series of supraoculars. 



The tongue is obtuse, and slightly notched anteriorly ; its surface 

 being covered with villous papillae. The teeth are short, and almost 

 uniform in size; the anterior ones being simply conical, whilst they 

 are tricuspid on the sides of the jaws. The nostrils are situated near 

 the apex of the snout, perforating each one single plate, surrounded by 

 three or four small scales. The neck is slightly contracted ; the late- 

 ral concavity, under the fold, is lined with small, granular scales. The 

 anterior edge of the auricular aperture exhibits a serrated appearance, 

 owing to the presence thereon of a few subtriangular scales ; the tym- 

 panum is situated somewhat below the surface. The sides of the neck 

 are covered with small scales, similar in shape and structure to those 

 of the back and sides of the body. The body is rather short and 

 depressed. The tail is depressed at the base, and conical posteriorly. 

 The scales which cover the upper regions are, generally speaking, well 

 developed, imbricated, keeled, and acuminated. The abdominal scales 

 are smooth, smaller than the dorsal ones, and oftentimes notched, ace- 

 rated, bifid, or multifid. 



The limbs are proportionally well developed, and in harmony with 

 the size of the body. A series from twelve to sixteen femoral 

 pores may be observed on each side, the posterior aspect of the thighs 

 being minutely scaly. 



