864 APPENDIX C. — REPTILES. 



two posterior angles of the vertex, instead of being acute, as in 

 Phr. douglassi, are rounded, without anj prominent knob or spine. 

 Along the superciliary ridge which overlaps the eyes, the plates 

 are the largest, at least, five of them, there being two very small 

 ones nearly above the middle of the eye. The occipital area 

 exhibits three subcircular plates in its centre, larger than the sur- 

 rounding ones. A group of large subspinous plates is likewise 

 observed at the base and in advance of the occipital spines. The 

 plates on the snout and along the upper jaw are small and incon- 

 spicuous, except the marginal row, on account of an acute pro- 

 jection of each of them. The nose is flattened to excess, slightly 

 concave, and the nostrils are situated at the inside of the super- 

 ciliary ridge ; thus placed in front (fig. 4). The eyes are cir- 

 cular. The lower jaw wants the first row of large plates which 

 we have seen in Phr. douglassii, but the one which exists is so 

 much more developed than in the latter, and composed of six very 

 conspicuous plates on each side and two small ones (fig. 2 and 3). 

 Between this row of plates and the margin of the jaw there is an 

 area, covered, on its anterior portion, with two, and, near the 

 angle of the mouth, with three rows of small and polygonal scales. 

 On the lower surface of the head, from the chin to the throat, the 

 scales are small and irregular ; on the sides, however, and only 

 for the posterior half of that distance, a row of from five to seven 

 acute-edged scales may be seen. The folds of the neck do not 

 exhibit any thing peculiar under the throat, but, on the sides and 

 behind the ear, they are surmounted with pyramidal and raised 

 scales. The auditory aperture is comparatively small — much 

 smaller than in Phr. douglassii. The pyramidal and raised scales 

 of the back are but little prominent. There is but one abdominal 

 series of the latter, as in Ph. douglassii, originating behind the 

 fore legs, but not extending so far backward as in others. The 

 plates in the post-anal groove form two rows, the first composed 

 of six, the second and posterior one of four only. The femoral 

 pores are but few, from six to seven on each side, and quite dis- 

 tant from each other. 



The head and tail are brown above, the upper part of the body 

 ash-coloured ; yellowish and unicolor below. On the sides of the 

 neck is a large patch of black, and two similar ones, but narrow 

 and undulating, on the back. Faint indications of transverse 

 bands of black are observed on the tail. 



Collected by Captain Stansbury about the Great Salt Lake. 



