CROCOUILIANS, LIZARD8, AND SNAKES. 



289 



It is, however, evident that there is really but one species, as many 

 specimens are so strictly intermediate as to render it very difficult to 

 say where they should be assigned. In the largest individuals, however, 

 the average of characters as assigned is generally preserved. 



This lizard is the characteristically abundant form of western Texas. 

 I found it in the iirst plateau country to the heads of the Medina and 

 Upper Llano. Mr. Boll states that it does not range east of Fort 

 Worth, in northern Texas. I did not observe it in the low country of 

 Washington County, It evidently belongs to the plateau fauna. It 

 runs with great rapidity, with its tail generally curved upward, dis- 

 playing the black spots on the lower side. It prefers rocky ground, 

 and does not ascend trees under ordinary circumstances. 



Holbroolda texana ranges over part of the Sonoran subregion at 

 least. I have taken it at Lake Valley, New Mexico, and E. Wilkinson 

 at the city of Chihuahua. The western limit of its range has not been 

 determined. 



Holhrookia texana Troschel. 



HOLBROOKIA PROPINQUA Baird and Girard. 



. Holhrookia propinqiia Bauii> and Gikard, Proc. Acad. Nat. Sci. Phila., VI, August, 



1852, p. 126 (Indianola to San Antonio).— Bocourt, Miss. Sc. Mex., Kept. 



lS74,p. 162.— Cope, Bull. U.S. Nat. Mus., No. 17, 1880, p. 15.— Boulenger, 



Cat. Liz. Brit. Mus., II. 1885, p. 208. 



Scales on back very small. Not appreciably larger than those on 



sides. Head flattened; plane from middle of orbit to snout, narrow; 



longer than broad. Ilind foot two-fifths the head and body; free 



part of largest toe considerably longer than cephalic plates. Temporal 



plates large, few in number; fully equal to those margining under 



labials behind. Upper labials seven. 



Above olive or ashy gray or green, with dorsal blotches, color gener- 

 ally similar to those of H. macidata, but the lateral spots (in anterior 

 half of sides) are more elongated vertically, and extend into the gray 

 of the sides. They are scarcely visible from below. 



Holbroolda propimiua is easily distinguished from other species of the 

 genus. The tail is slender, cylindric, and longer than the head and 

 body; the hind foot is elongate, being two-fifths the length of the head 

 NAT MUS 98 — 19 



