t 



BRACHYLOPHUS FASCIATUS. 375 



DAUD. Hist. nat. Kept. Ill, 1805, 352. MERE. Tent. Syst. Amph. 1820, 48. 

 GRIFF. Anim. Kingd. IX, 1831, 39. 



Brachi/lophus fasciatus, Cuv. R6gn. Anim. 2d ed. II, 1829, 41. GUER. Iconogr. 

 du Regn. Anim. Kept. 1833. PI. ix, fig. 1. WAGL. Naturl. Syst. Amph. 1830, 151. 

 GRAY, Synops. Kept, in Griff. Anim. Kingd. IX, 1831, 37. WIEGM. Herp. Mexic. i, 

 1834, 16. DOM. & BIBR. Erpet. gen. IV, 1837, 226. FITZ. Syst. Kept, i, 1843, 55. 

 GRAY, Catal. Lizz. Brit. Mus. 1845, 187. BUM. & A. BUM. Catal. m6th. Kept. Mus. 

 d'hist. nat. i, 1851, 64. 



Ctenosaurus sieberi, FiTZ. 



OBSERV. The specimens preserved are dried skins, having lost, in 

 a great measure, their natural shape, especially the head, neck, and 

 limbs. The general aspect of the animal, however, is admirably given 

 in the accompanying figure, made from life at the time the specimens 

 were collected. The soft parts of the inside of the mouth, together 

 with the palatine teeth, are entirely removed, the maxillary teeth 

 being the only organs left ; they are largest posteriorly than upon the 

 svinphyses of the jaws. 



DESCR. The upper surface and sides of the head are protected by 

 small, nearly equal, and smooth polygonal plates : the occipital being 

 but a trifle larger than the rest, and depressed upon its centre. Those 

 occupying the extremity of the snout, in the immediate neighborhood of 

 the rostral, as well as the phrenic region, are also somewhat larger than 

 upon the frontal region. As to the nostrils, they perforate one plate, 

 situated above the first labial. The lower labials are more conspicu- 

 ous than the upper ; three series of elongated plates may be observed 

 under the branches of the dentary, in contiguity with the labials. 

 Otherwise, the scales upon the inferior surface of the head are quite 

 small. Over the auricular aperture, and near the surface, is stretched 

 the tympanum, subcircular or elliptical in shape, obliquely situated 

 behind the angle of the mouth. 



The body is compressed, deeper than broad, and tapering poste- 

 riorly, being nearly as thick at the shoulders as on the middle of its 

 length. A small crest may be observed along the dorsal line, extend- 

 ing from the occipital region to beyond the anterior third of the tail, 

 most conspicuous upon the neck and opposite the shoulders, diminishing 

 posteriorly, and gradually vanishing away amongst the keeled scales 

 of the posterior half of the tail. A fold of the skin is placed longitu- 

 dinally along the throat ; another along the sides of the neck, and 



