Hurter — Herpetology of Missouri 133 



38. Phrynosoma cornutum Harlan. Horned Lizard. 

 Horned Toad. 



Agama cornuta, Tapaya cornuta, Tropidogaster cornutus, Tropidogas- 

 ter hufonium, Lacerte tapayaxin, Phrynosoma dufonium, Phrynos- 

 oma harlanii, Phrynosoma orMculare, Phrynosoma planiceps, Phry- 

 nosoma cornutum. 



Description. — Head short, muzzle descending steeply in profile. Nos- 

 trils directed forward and separated from the scales of the canthus 

 rostralis by a single scale. Posterior superciliary angle produced into a 

 short horn. Temporal region expanded, supporting three horns, the 

 anterior short, the median equal to or longer than the posterior one; 

 all directed outward and a little upward. Occipital horns moderate, 

 acute, well separated, slightly divergent, and directed more than 45 

 degrees upward. Scales of front and vertex rugose. A row of three 

 or four conic scales anterior to the occipitals, and one posterior median 

 occipital not very long. Infralabials prominent and acute posteriorly, 

 the last equal to or longer than the first temporal. Gular scales keeled 

 and a row of enlarged ones on each side. Two groups of spines on each 

 side of the neck. Large scales on humerus, extending across the cavi- 

 cular region. Several gular folds, irregular. 



Back with some very large erect spinose tubercles, which form a 

 series of three or four on each side of the vertebral line. Two lateral 

 series of spines, the upper the larger. Pectoral and ventral scales more 

 or less distinctly keeled. Femoral pores in males four to twelve, not 

 extending on the prae-anal region, sometimes very indistinct. No en- 

 larged post anal scales. Superior surface of humerus and cubitus cov- 

 ered with large keeled and mucronate scales. Femur and tibia covered 

 above with smaller keeled scales, intermixed with a few large spinose 

 ones. Tail with a marginal row of spines on the basal half and inter- 

 mixed with larger scales on the superior surface. Scales on the infe- 

 rior side of lim'bs and tail, except the femur, keeled, the tail most 

 strongly. (Cope.) 



Color. — Grayish or brownish above with a more or less marked light 

 dorsal streak, and dark brown spots at the base of the larger dorsal 

 spines; a large dark brown spot on each side of the nape; two cross 

 streaks between the superciliary ridges, a band from the eye to the 

 angle of the mouth, and from the eye to the middle temporal spine, 

 dark brown. Lower surface yellowish, uniform, or with some brownish 

 spots. 



Size. — From tip of snout to vent 110 mm.; from vent to end of tail 

 46 mm. 



Habitat. — The range of the Horned Toad extends from 

 Chihuahua, Mexico, north through Texas, southern Kan- 



