852 APPENDIX C. — REPTILES. 



from tlie body by a contracted neck. The vertical plate is elon- 

 gated and contracted on its middle. The posterior pair of frontal 

 plates has almost twice the size of the anterior pair. The eyes are 

 proportionally very large, protected below by the fourth and fifth 

 labial shields, anteriorly by a large and a small orbital plate, and 

 posteriorly by two of nearly the same size, if not of the same shape. 

 The loral is proportionally very much developed. The nostrils are 

 prominent. There are eight labial plates to the upper jaw and 

 seven to the lower. The scales are smooth, elongated on the back, 

 and posteriorly pointed, while on the sides they are broader, and 

 the row contiguous to the ventral shield is composed of scales 

 broader than long. On the posterior part of the head, as usual, 

 the scales are subcircular, or polygonal, and much the smallest. 

 On the tail they assume rather a lozenge shape. There are one 

 hundred and seventy-five ventral shields from the throat to the 

 vent. 



The colour is brown above and yellow underneath, with a bluish 

 tint along the sides of the abdominal region. On the back there 

 is a row of transversely elongated patches of deep brown, bordered 

 with black. The sides are spotted with three indistinct rows of 

 small spots of brown and black intermixed. 



This species was found by Captain Howard Stansbury's party, 

 in the valley of the Great Salt Lake. 



, Hetorodon nasicus, Baird and Girard. 



Spec. chae. — Minute and numerous frontal plates instead of two large pairs ; 

 two brown stripes over the head ; temporal patch very broad. 



The essential character which distinguishes this species from 

 the S. platyrhinos and H. simus, which it most resembles, con- 

 sists in the presence of numerous small scales between the vertical 

 and rostral plates ; that is, on the space which is occupied by the 

 two pairs of frontal plates. In jff". simus, it is true, very minute 

 scales may be occasionally observed on the middle line between 

 the vertical, rostral, and frontal plates ; but when this is the case, 

 the latter are not reduced to the small size which they have in the 

 species which we here describe. 



The vertical plate in ff. nasicus is circularly subhexagonal. 

 The superciliaries are longer than the vertical, and thus longer 

 than broad, while the occipital are broader than long. The nasal 



