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Show 852 APPENDIX C.- REPTILES. from the body by a contracted neck. The vertical plate is elongated 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 fleep 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 NASICTTS, Baird and Girard. SPSO. CHAB.- Minute and numerous frontal plates instead of two large pairs; two brown stripes oyer the head; temporal patch very broad. The essential character which distinguishes this species from the H. platyrhinos and H. simtis, which it most resembles, consists 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 H. 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 H. nasictts is circularly subhexagonal. The superciliaries are longer than the vertical, and thus longer than broad, while the occipital are broader than long. The nasal |