no. 2078. REPTILES OF NORTHWESTERN NEVADA— RICHARDSON. 425 



California, collected by C. V. Burke. One was seen by us in a canyon 

 near Tahoe City on June 27. This is apparently the first record of 

 this species in the Lahontan Basin since it has previously been found 

 only on the western slope of the Sierra Nevada Mountains (Van 

 Denburgh, 1898). 



Status and variation. — The specimens are very typical. The 

 temporal scales are keeled, except in the smallest individual, in which 

 the keels are obsolete. There are 16 rows of strongly keeled dorsal 

 scales, a single interocular, a large azygous prefrontal, larger than 

 either of the paired prefrontals and the dark ventral lines are absent 

 in one, present between the ventral scales in another, and indefinite 

 in the smaller specimen. 



CNEMIDOPHORUS TIGRIS Baird and Girard. 



Locality. — CnemidopTtorus tigris was an abundant species at 

 Derby, Wadsworth, Pyramid Lake Indian Agency, and along Pyramid 

 Lake to The Willows. It was also taken at Carson City and was seen 

 at Winnemucca, in Humboldt County, and Palisade, Eureka County, 

 Nevada. It has been taken before in the Lahontan Basin near 

 Wadsworth, Washoe County; Carlin Elko County and Pine Forest 

 Mountains (vicinity of Big Creek Ranch), Humboldt County, Nevada. 



Status and variation. — The 43 specimens obtained are identical 

 with specimens in the Stanford University collection from southern 

 Idaho (vicinity of Blue Lake, Lincoln County, and Conant, Cassia 

 County) . 



The color variations in this species have been described by Stej- 

 neger (1893, p. 199), and more recently by Meek (1905, p. 13). 

 Specimens from the Lahontan Basin appear to vary in the same man- 

 ner as those from southern Nevada and California. The abundance 

 of black pigment on the throat and breast as noted by Stejneger is 

 not dependent upon size or sex. The dorsum likewise has a variable 

 color pattern. 



Habits. — This species was found most abundantly at Pyramid Lake 

 among the low-growing desert bushes. At Carson City a number of 

 specimens were taken in a growth of Artemisia tridentata. In the east- 

 ern part of the basin, it was encountered but twice, at Winnemucca and 

 Palisade where it was seen in growths of Artemisia tridentata. 



When frightened, O. tigris seeks the shelter of a bush and will often 

 hide in the holes of Citellus mollis and other mammals. Occasionally 

 it was observed to climb into bushes. 



The stomachs of six individuals taken on May 31 were filled with 

 large white larvae and pieces of gravel. A single spider was also 

 found in one specimen. The insect prey of this species, according 

 to the observations of Professor Snyder, is picked up by means of 

 the long slender tongue. 



