REPTILES OF THE PACIFIC COAST. 



81 



Upper head-shields smooth, moderately large, and very 

 slightly convex; interparietal much largest. Frontal 

 usually divided transversely. Parietal, frontoparietal, 

 and frontal plates separated from enlarged supraoculars 

 by a series of smooth plates or granules. Superciliaries 

 long, wide, and strongly imbricate. Middle subocular 

 very long, narrow, and strongly keeled. Rostral plate of 

 moderate height, but great width. Labials long and 

 low. Below lower labials and behind large pentangular 

 symphyseal some series of plates larger than gulars. 

 Latter of moderate size, smooth, imbricate, and usually 

 emarginate posteriorly. Ear-opening large, slightly 

 oblique, with an anterior denticulation of smooth accu- 

 minate scales. Back with equal-sized, keeled, pointed 

 scales arranged in nearly parallel longitudinal rows. 

 Scales on sides similar to those on back but much smaller 

 and directed obliquely upward. No longitudinal folds 

 and no transverse fold on throat. Superior surfaces of 

 limbs provided with large, keeled scales. Posterior sur- 

 face of thigh covered with small, accuminate, keeled 

 scales. Ventral scales much smaller than dorsals 



