92 CALIFORNIA ACADEMY OF SCIENCES. 



three to six temporals, one occipital, and one postorbital 

 on each side, and one small interoccipital. Sometimes 

 with small spines above and between temporals and 

 often in front of occipital spines. Temporal scales with 

 ridges running in the general direction of temporal 

 spines. Other upper head-scales convex and almost or 

 quite smooth. Several longitudinal series of gular 

 scales enlarged and spinose, but becoming smaller to- 

 ward median line, and continued on gular fold or folds. 

 A series of five or six spinose sublabials, often continued 

 posteriorly by smaller plates. Below corner of mouth, 

 a very broad spine followed by a long slender one. Two 

 groups of spines on each side of neck, lower usually 

 larger. Back and tail with large, scattered, somewhat 

 elevated, keeled, tubercular scales, between which smaller 

 scales and granules. Two rows of peripheral spines; 

 lower series shorter than upper and composed of smaller 

 spines. Tail edged with a single row of lateral spines 

 and bearing a small group of slender spines just behind 

 thigh. Scales on anterior surfaces of limbs large, pointed, 

 and strongly keeled. Those on chest, abdomen, and 

 proximal part of ventral surface of tail smooth, but 

 those on terminal portion of tail keeled. Tympanum 

 not covered with scales. Long series of (12 to 18) 

 femoral pores present. Males usually with enlarged 

 postanal plates. 



The ground color above is brownish, yellowish, red- 

 dish, or grayish, usually darker laterally. A large brown 

 patch occupies each side of the neck. On the back are 

 undulate cross-bands or large irregular spots of dark 

 brown, usually edged posteriorly with yellow or white. 

 Similar markings are seen on the tail. The head is 

 usually yellow, but may be clouded with slate. Its larger 

 spines are often reddish. The lower surfaces are yellow 



