﻿4. DIPSOSAURUS 79 



Difsosaurus dorsalis lucasensis Van Denburgh, Proc. Cal. Acad. Sci., 

 Ser. 4, Vol. 10, 1920, p. 33 (type locality, San Jose del Cabo, 

 Lower California, Mexico); Van Denburgh & Slevin, Proc. 

 Cal. Acad. Sci., Ser. 4, Vol. XI, No. 4, 1921, pp. 51, 56; Nelson, 

 Mem. Nat. Acad. Sci., Vol. XVI, 1921, pp. 114, 115. 



Description. — Head short, rounded and rather high. 

 Nostril opening laterally in a single rounded plate which is 

 separated from the large rostral usually by one row (78%) 

 but sometimes by two rows (15%) of granules. Supra- 

 ocular regions, separated from each other by two or three 

 series of small convex plates, covered with 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 enlarged plates. Gulars small, either convex or flattened. 

 Rye-lids very slightly fringed. Ear-opening very large, 

 almost vertical, and with a very weak anterior denticulation. 

 Dorsal crest composed of slightly enlarged, strongly keeled 

 scales. Other dorsals small, keeled, juxtaposed, and in series 

 which converge toward the dorsal line posteriorly. Ventrals 

 larger than dorsals, smooth and imbricate. 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 16 to 25 in number; average 

 on 100 thighs, 18.46. 



The general color is grayish brown above, variously 

 barred and reticulated with dark brown and slate, and spotted 

 or blotched with light gray or yellowish white. These 

 markings are often less distinct near the vertebral line than 

 laterally. The upper surface of the head is grayish, brown- 

 ish, or yellowish, more or less clouded, often darkest on the 



