ZOOLOGY REPTILES. 6 



scales upon the back, very distinctly carinated ; several rows of large scales beneath the infra- 

 labials, the two anterior of the inferior rows much the largest ; collar scaly ; aural apertures 

 strongly denticulated anteriorly ; sides of neck folded ; a fold over the shoulder ; occipital scale 

 large, in contact on each side with the supra-orbital ridge ; scales upon muzzle for the most 

 part narrow ; behind them two transverse rows, the first containing three, the second but two 

 plates; two single plates upon the vertex, the anterior the largest; six narrow pentagonal 

 plates upon each orbit, bordered internally with a row of small scales ; 46 teeth in upper jaw, 

 44 in lower ; color of body yellowish, mixed with brownish and black spots ; extremities 

 yellowish, with dark colored transverse bands ; tail of same color above as body, under surface 

 silvery white, with blackish spots ; eleven femoral pores. 



Dimensions. — Length of head, -I inch ; greatest breadth, f inch ; length of head, neck, and 

 body to vent, IJ inch ; of anterior extremities to extremity of longest toe, J inch ; of posterior 

 to extremity of longest toe. If inch ; of tail, 4^ inches ; total length, 6| inches. 



Habitat. — Southern jjart of Upper California. 



Q-BNBKAL Kemarks. — The contrast between the large carinated scales upon the back and the 

 small ones upon the sides, resembling granulations, is striking ; the long and slender tail is 

 also remarkable. In these respects, Uro-saurus is allied to Tacliydromus, but the plates upon the 

 head are very diiferent. 



SCELOPORUS, Wiegmann.i 



SCELOPOKUS MAGISTEE, Nob. 



Sp. Char. — Larger than any known species of Sceloporns, and remarkable for its large and 

 strongly carinated scales, which are very much denticulated posteriorly ; anterior margin of 

 aural apertures strongly denticulated ; upper part of head, body and extremities, and tail straw 

 color, without spots or blotches ; a black triangular blotch upon each side of the neck, in front 

 of the shoulder, the base below ; two large bluish green blotches upon the abdomen, one on each 

 side and one upon the neck ; the rest of the under surface light straw color ; tail long, very thick 

 at base, tapering near the point ; twelve femoral pores on each side. 



Dimensions. — Length of head, neck, and body to vent, 4| inches ; greatest breadth of head, 1^ 

 inch ; length of head, 1|- inch ; of tail, 5 inches ; of anterior extremities, 1^ inch ; of anterior 

 foot to extremity of longest toe, 1 inch ; of posterior extremities, If inch ; of foot to extremity of 

 longest toe, If inch ; total length 9| inches. 



Habitat. — Near Fort Yuma, at junction of Colorado and Gila, also near Tuson, in Sonera, 

 upon a rocky soil. 



Gen. Obs. — This species is remarkable for its large size and greatly developed spines. It is a 

 much larger animal than S. spinosus of Wiegmann, and wants the quadruj^le series of dark 

 colored spots that exist in that animal. The posterior margins of the scales are strongly den- 

 ticulated, which is not the case in 8. spinosus, one of the characters of which is " squamis pauci- 

 dentatis." From 8. Jiorridus Wieg. it differs in coloration, arrangement of plates upon the head, 

 and in the number of femoral pores, which in the latter are 4-5. 



(1) Tropidolepis, Cuvier. 



