492 



MB. G. A. BOITLENGEE ON THE 



[May 18, 



D. Femoral pores 11-17 ; auricular scales usually much 

 longer than broad. 



Brown, greyish, or olive above, usually with a more or less 

 distinct light stripe along each side of the back ; more or less 

 regular dark brown or blackish bands may be present across the 

 back ; these bands may be broken up into spots or so extend as 

 to obscure the ground-colour. Dark bars are usually present 

 across the digits, but may be absent, irrespective of the structural 

 characters or the localities. The type of »S'. clarhii, from Arizona, 

 is described as uniform yellowish green above, and we possess a 

 uniform greenish specimen from Fort Lowell, recently received from 

 the Stanford University through Prof. Gilbert as S. clarlii, with 

 which it agrees in its ear-scales ; whilst a second specimen from the 

 same locaHty, received under the same name, and agreeing in the 

 ear-scales, has the dorsal cross-bars of S. spinosus and barred toes. 

 S. magister is described by Hallowell (from Fort Turaa and Tucson, 

 Arizona) as " straw-colour above, \Aithout spots or blotches." Our 

 specimens from Arizona, answering to the definition of 'S^. magister 

 given by Stejneger, vary much in coloration nnd cannot be distin- 

 guished in this respect from specimens from Mexico, referred to 

 the typical S. sjjinosus, and Texas, the latter being considered by 

 Stejneger as a distinct species, S. Jloridanus, Baird. This is 

 described by Baird as " greenish yellow, with two broad yellow 

 stripes, five scales apart ; back with distinct transverse blackish 

 bars." A black blotch is usually present in front of the arm, and 

 may ascend up the sides to form an incomplete nuchal collar. 

 This is best marked in some specimens from Arizona, Colorado, 

 and Presidio near Mazatlan. 



1 am unable to reconcile the differences in the coloration of the 

 upper parts with any structural characters. The same may be said 

 of the coloration of the lower parts. 



