Vou. IIT] VAN DENBURGH AND SLEVIN—ARIZONAN REPTILES 409 
times, 20 twenty-two times, 21 thirteen times, 22 eleven times, 
23 once, and 24 once. The average number is 19.87. 
41.—Cnemidophorus tigris Baird and Girard 
Seventy-three Arizonan specimens of this lizard are at hand. 
Fifty-three of these were collected at Yuma in March, June, 
September, October, and December. Nineteen were shot 
at Papago Wells, southeastern Yuma Co., April 16-22, 1912. 
One (No. 35328) was secured at Ajo, Pima County, April 16- 
22, 1912. None of these specimens have black throats and 
chests, although these regions may be slaty with a few black 
spots. The specimen from Ajo is as typical as the others, al- 
though this locality must be near the eastern limit of the range 
of this form, for typical C. melanostethus was collected at Gun- 
sight, Pima Co., only about forty miles southeast. 
Femoral pores in forty of these specimens vary from seven- 
teen to twenty-five; being 17 three times, 18 four times, 19 ten 
times, 20 fourteen times, 21 eighteen times, 22 eleven times, 
23 nine times, 24 four times, 25 twice, and 5 injured. The 
average number is 20.89, as against 20.4 in forty specimens 
from Yuma recorded in a former paper. 
43.—Leptotyphlops dulcis (Baird and Girard) 
We did not collect any specimens of this worm snake. So 
far as we can learn it has not been recorded from Arizona: 
but its occurrence there was shown by a typical specimen which 
Mr. Herbert Brown collected at Yuma and sent to me a short 
time before the great San Francisco fire of April, 1906, in 
which the specimen unfortunately was destroyed. Professor 
Brown of the University of Arizona told us that he had seen 
both kinds of worm snakes at Tucson, this species being rep- 
resented by a single specimen collected on the grounds of the 
Carnegie Desert Laboratory in 1911. 
44.—Siagonodon humilis (Baird and Girard) 
We have at hand four specimens from Arizona. Three are 
from Tucson. Nos. 33835 and 33836, collected April 17, 1895, 
and No. 35325 without date were presented to us by Professor 
Brown of the University of Arizona. The fourth specimen, 
No. 33849, was collected about the middle of May, 1912, in the 
foothills of the Catalina Mts., about eighteen miles northeast of 
