344 CALIFORNIA ACADEMY OF SCIENCES. 



and are possibly, though improbably, very old males of 

 that species. It seems best for the present to consider 

 them distinct, and, since the two forms were found to- 

 gether, one cannot be regarded as a subspecies of the 

 other. One specimen (2936) is labeled "Arizona," the 

 other (2 141) was shot near Fort Lowell. 



Cnemidophorus tigris melanostethus (Cope). 



I have been unable to detect any difference between 

 Cnemidophori from southeastern Arizona and specimens 

 of C. tigris from Idaho and California, except that adults 

 from the former locality have throats suffused with intense 

 black, while in C. tigris this region is usually grayish 

 slate. The types of C. melanostethus are more nearly 

 like C. tigris than like the specimens from southeastern 

 Arizona, but their paleness may be seasonal rather than 

 geographical. When more specimens have been col- 

 lected it may become necessary to regard melanostethus 

 as a synonym of tigris, and perhaps to supply a new 

 name for the form found in southeastern Arizona. 



A large number of specimens was obtained near Fort 

 Lowell, in Rucker Canon, and in the Huachuca Moun- 

 tains. 



Cnemidophorus arizonae, new species. Plate xlix. 



Diagnosis. — Nasal in contact with second supralabial; 

 postnasal and first supralabial not in contact; three large 

 preanals, the largest behind; dorsal granules equal;- nos- 

 tril anterior to nasal suture; eight longitudinal rows of 

 ventral plates; femoral pores fourteen; frontoparietals 

 distinct; supraoculars four; caudal scales oblique ; limbs 

 unicolor; seven light longitudinal lines, the median dor- 

 sal line as narrow and distinct as the lateral ones. 



Type. — Leland Stanford Junior University Museum, 



