172 University of California Publications in Zoology  [Vou.17 
Puerta Valley (U.S. Nat. Mus.; Stephens, MS). Occurs in the Upper 
Sonoran life-zone. Lives in crevices of rock outcrops. 
Xantusia riversiana Cope 
Island Night Lizard 
OriainaL DescripTrion.—NXantusia riversiana Cope, Proe. Acad. 
Nat. Sci. Phila., 1883 [1884], pp. 29-32 (see also Amer. Nat., 13, 1879, 
p. 801). 
Type Locauiry.—California; fixed as San Nicolas Island, Ventura 
County, California, by Rivers (Amer. Nat., 23, 1889, p. 1100). 
Common Name.—Rivers’s Lizard. 
Rance.—Known only from San Nicolas Island, Santa Barbara 
Island, and San Clemente Island. The record from Santa Catalina 
Island (Van Denburgh, Proe. Calif. Acad. Sei., ser. 3, zool., 4, 1905, 
p- 16) is now questioned (Van Denburgh, Proe. Calif. Acad. Sei., 
ser. 4, 4, 1914, p. 133). Lives beneath stones and in wind-drifted 
debris at bases of bushes. 
Family TEIIDAE 
Cnemidophorus tigris tigris Baird and Girard 
Desert Whip-tailed Lizard 
OrIGINAL DescripTiION.—Cnenuidophorus tigris Baird and Girard, 
Proe. Acad. Nat. Sei. Phila., 6, 1852, p. 69. 
Type Locauiry.—Valley of the Great Salt Lake, Utah. 
Synonyms.—Cnemidophorus gracilis Baird and Girard, Proce. 
Acad. Nat. Sci. Phila., 6, 1852, p. 128 (type from desert of Colorado) ; 
Cnemidophorus tessellatus tigris, part; Cnemidophorus tessellatus 
tesscllatus, part; Cnemidophorus sexlineatus var. tesselatus ; Cnemi- 
dophorus sexlineatus var. bocourtii Boulenger, Cat. Lizards Brit. Mus., 
2nd ed., 2, 1885, p. 367 (types from California). 
Common Names.—Desert Whip-tail; Swift Jack; Tessellated 
Lizard; Tiger Armor-bearer; Tiger Lizard. 
Rance.—Deserts of southeastern California. Extends north to 
Benton, Mono County (Mus. Vert. Zool.) ; west to Gray’s (altitude 
6000 feet, near Kearsarge Pass) and Carroll Creek, in Inyo County 
(Mus. Vert. Zool.), and to desert bases of San Gabriel, San Bernardino, 
San Jacinto and other mountain ranges to the southward. Intergrades 
with C. t. mundus through Walker Pass, and with C. t. stejnegeri in 
