74 3. IGUANID^ 



Diposaurus dorsalis dona/is Van Denburgh, Proc. Cal. Acad. Sci., Ser. 4, 

 Vol. X, No. 4, 1920, pp. 33, 34; Van Denburgh & Slevin, Proc. 

 Cal. Acad. Sci., Ser. 4, Vol XI, 1921, pp. 28, 50, 56; Nelson. 

 Mem. Nat. Acad. Sci., Vol. XVI, 1921, pp. 114, 126. 



Description. — Head short, rounded and rather high. 

 Nostril opening laterally in a single rounded plate which is 

 separated from the large rostral usually by two rows (83%) 

 but sometimes by one row (10%) of granules. Supra- 

 ocular regions, separated from each other by two or three 

 series of small convex plates, covered with very small plates 

 and granules. A large subocular, followed and preceded 

 by several smaller ones. A series of long, strongly imbricate 

 superciliaries. Labials small, about equal in size, and from 

 eight to 11 in number in each series. Symphyseal plate 

 nearly triangular, and forming the apex of a V-shaped series 

 of slightly enlarged plates. Gulars small, either convex or 

 flattened. Eyelids very slightly fringed. Ear-opening very 

 large, almost vertical, and with a very weak anterior den- 

 ticulation. Dorsal crest composed of slightly enlarged, 

 strongly keeled scales. Other dorsals small, keeled, juxta- 

 posed, and in series which converge toward the dorsal line 

 posteriorly. Ventrals larger than dorsals, smooth and im- 

 bricate. Sides covered with small granular scales. Tail 

 long, tapering, slightly crested and with whorls of obliquely 

 keeled scales. Limbs rather long, covered with keeled 

 scales and granules. Femoral pores varying from 18 to 26 

 in number; average in 131 thighs 21.98. 



The general color is grayish brown, variously barred and 

 reticulated with dark brown and slate, and spotted or 

 blotched with light gray or white. These markings are 

 often less distinct near the vertebral line than laterally 

 where they often tend to form longitudinal lines. The 

 upper surface of the head is grayish, brownish, or yellowish, 

 more or less clouded with slate, darkest on the supraocular 



