REPTILES 189 



10. Phrynosoma Wiegmann. Horned toads; horned lizards. 

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

 with 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 Plirynosoma 



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. cornutitm. 



Co In California P. blainvillii. 



C3 In Arizona P. solare. 



b2 Horns small or rudimentary (Fig. 108); i row of marginal 

 spines or none. 



Ci No enlarged marginal spines present P. modestum. 



C2 One row of enlarged marginal spines present P. douglassii. 



ao Tympanum covered with scales. 



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



b2 Horns long; 16 to 20 femoral pores P. m'callii. 



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

 Length 150 mm. ; tail 45 mm. ; width of body 60 mm. ; color gray, spotted 

 with brown and with a median yellow band; head spines very long: 

 Kansas and Nebraska to Texas and Colorado; common. 



Fig. 107. — Head of Phrynosoma Fig. io8. — Head of Phrynosoma 



cornutum (from Cope). hernandesi (from Cope). 



P. blainvillii Gray. Length 1 50 mm. ; tail 56 mm. ; color light brown : 

 California, southward and eastward of San Francisco; common. 



Subspecies of P. blainvillii 



P. b. blainvillii Gray. Southern California; Lower California. 



P. b. Jrontale Van Denburgh. In the northern portion of the range. 



