200 VERTEBRATE ANIMALS OF THE UNITED STATES 



S. occidentalis B. & G. (Fig. 105). Length 200 mm.; tail 100 mm.; 

 color greenish gray, with 2 rows of wavy cross bars on the back; legs 

 very long: the Great Basin and mountain ranges of the Pacific region 

 from Oregon and Idaho to Nevada and southern California; common 

 in rocky districts. 



S. woodi Stejneger. Length 103 mm.; tail 65 mm.; fourth toe 

 extremely long : central and east-central Florida. 



10. Phrjrnosoma Wiegmann. Horned toads; horned lizards. Body 

 short, wide and flattened; tail short; hinder border of head armed with 



Fig. 107. — Wedidoi Phrynosoma corniitnm Fig. io8. — tieaAot Phrynosoma hernandcsi 



{from Cope). (from Cope). 



long, sharp, horn-like spines; long spines also often along the sides of 

 the body and tail: about 17 species, in the desert regions of the south- 

 west and of Mexico; terrestrial, living largely on insects; viviparous; 

 harmless. 



Key to the United States Species of Phrynosoma 



ai Tympanum not covered with scales. 



bi Horns long and large (Fig. 107) ; 2 rows of enlarged marginal 

 spines on the sides of the body. 



Ci In the Great Plains region P. cormUmn. 



Co In California P. hlainvilli. 



C3 In Arizona P. solarc. 



hi Horns small or rudimentary (Fig. 108); i row of marginal 

 spines or none. 



Ci No enlarged marginal spines present P. modcstuvi. 



C2 One row of enlarged marginal spines present. 



di Horns reduced to tubercles P. douglassi. 



do Horns small but distinct. 



ei Median horns directed backwards P. hernandesi. 



e2 Median horns directed upwards P. ornatissiynuni. 



a2 Tympanum covered with scales. 



bi Horns short; 6 to 12 femoral pores P. platyrhinos. 



h<i Horns long; 16 to 20 femoral pores P. m'calli. 



P. cornutum (Harlan). Common horned toad (Fig. 107; Fig. 109). 

 Length 1 50 mm. ; tail 45 mm. ; width of body 60 mm. ; color gray, spotted 



