APPENDIX C. — REPTILES. 339 



broad, arranged in annular rows, or else verticillated and slightly 

 carinated. The tail is cylindrical, and two and a-half times the 

 length of the body and head together : it tapers gradually and 

 terminates in a point. 



The ground colour appears to have been bluish yellow, marked 

 with irregular patches of black. In some specimens, four longitu- 

 dinal yellow stripes may be seen extending from the occiput to the 

 base of the tail, and occasionally to a little distance on the latter. 

 In the young state, the black patches predominate, unite, and form, 

 as it were, the ground colour, and the yellow constitutes irregular 

 small spots, 



A series of individuals of different sizes were collected by Capt. 

 Stansbury in the valley of the Great Salt Lake. 



Genus Crotaphytus, Holbrook. 



Gen, char. — Head covered -with small and polygonal plates. The occipital pro- 

 per, minute. Teeth on the jaws, pterygoids and palatines, rudimentary on 

 the latter. Broad auditory aperture. Femoral pores present ; no anal ones. 

 Tail very long. 



Of the genus Orotaphytus, a typical form peculiar to North 

 America, but one single species has hitherto been discovered, the C. 

 coUaris, observed for the first time by Major Long's party, on their 

 expedition to the Rocky Mountains. The discovery of a second 

 species of this genus within the limits of the United States will be 

 received with interest : both of these have a very close generic re- 

 lationship, the differences being found in some minor details of their 

 structure. 



The generic characters are the following : — The occipital region, 

 vertex, and front are covered with small and polygonal plates. On 

 the superciliary region and around the nostrils the plates are 

 scarcely larger than the scales of the back. The odd occipital 

 plates are inconspicuous, being but very little larger than the sur- 

 rounding ones. The auditory apertures are broadly open. Teeth 

 exist on the maxillaries, palatines, and pterygoids ; conical, acute, 

 and slightly curved on the anterior part of the jaws, they are com- 

 pressed and tricuspid on the posterior. The palatine teeth are 

 rudimentary. The skin is folded under the throat. The scales of 

 the upper part of the body are polygonal, and smaller than those 

 of the lower part, or belly, and tail ; those under the head have 

 nearly the size of those of the back. The femoral pores are very 



