REPTILES 



193 



or yellowish blotches: deserts of Arizona and New Mexico; the only 

 poisonous lizard in the country or the world. 



Family 6. Xantusiidse. — Diminutive, cylindrical lizards with very 

 short legs, and granular scales on the sides and back; belly covered 

 with plates; 3 folds of skin on the throat; eye usually very large and 

 without eyelids; pupil vertical: about 5 species; in desert regions. 



Xantusia Baird. With the characters of the family: 4 species in 

 the United States. 



.Y. Jienshawi Stejneger. Length 140 mm.; tail 85 mm.; color 

 blackish brow^n, irregularly marbled wdth cream-colored lines: southern 

 California. 



Fig' ho. — Cnemidophorus sexlineatus (from Dilmars). 



X. riversiana Gope. Length 175 mm.; tail 87 mm.; color gray or 

 brown, spotted with brown or black: San Nicholas, San Barbara and 

 San Clemente Islands. 



X. vigilis Baird. Length 85 mm. ; tail 45 mm. ; color gray, yellow or 

 brown, speckled with brown: southeastern California; southern Nevada; 

 common in and beneath fallen yucca trees. 



Family 7. Teiidae. — Elongated lizards with a deeply bifid tongue 

 and sometimes rudimentary legs: i genus in the United States. 



Cnemidophorus Wagler. Race runners. Body slender; tail long 

 and tapering; scales granular above, plated beneath: 4 species in the 

 United States. 



C. sexlineatus (L.) (Fig. no). Swift. Length 250 mm.; tail 175 

 mm. ; color dark brown, with 6 yellow stripes on the body; belly bluish or 

 greenish: Maryland to Florida; westward to Colorado; up the Missis- 

 sippi Valley to Lake Michigan and South Dakota; common towards the 

 south; remarkable for its swiftness. 



C. sackii Wiegmann (C. giilaris Baird & Girard). Similar to C. 

 sexlineatus, but with a row of pale dots between each two stripes: 

 Oklahoma and Texas to Arizona and Utah. 



