ON THE ZOOLOGICAL POSITION OF TEXAS. 17 



ScelojJorus consohrimis B. & G. This lizard is found all over Texas 

 and is very variable in its characters. It always has about 28 trausver.so, 

 series of keeled unimucronate scales between the interscapula and inter- 

 femoral regions, and the lateral scales are not larger than the ventral. 

 The head scales are smooth. There may be three or two rows of supra- 

 orbitals between the internal and sui)erciliary scales. The colors are 

 often brilliant, especially in specimens from near San Antonio, where 

 the sides of the neck and head are often of a bright rufous, and the tail 

 reddish and yellowish brown at the base. It is very abundant from 

 Dallas west to Fort Concho, and southwest to San Antonio, and in the 

 first plateau region to the head of the Medina Eiver. It is found on the 

 ground, but always takes refuge in trees, running on and around the 

 limbs Avith great agility. 



Scelojporus scalaris Wiegm. This small and elegant species is abun- 

 dant in the region southwest of San Antonio, according to Mr. Marnock, 

 from whom I obtained siiecimens. I did not see it on the first i>lateau 

 or eastward. 



Sceloporus spinosus Wiegm., is abundant in Southwestern and Western 

 Texas, as far north as the heads of the Medina and Guadalupe. I did 

 not see it on the Llano. There are specimens in Mr. Boll's Dallas col- 

 lections, but this gentleman informs me that it is very rare so far east.. 

 It ranges in I'J'orth Texas chiefly west of Fort Worth. This lizard is es- 

 pecially arboreal, always ascending the trunks of trees when pursued. 

 In this situation its somber colors afford it concealment. These are of 

 different shades of brown without the brilliant blue and other colors of 

 the two species of the genus already named. 



Sceloporus poinsettii Bd. and Grd. The largest of its genus found in 

 Texas, this species has nearly the range of the S. spinosus. I found it 

 very abundant in the first plateau region as far as the upj^er waters of 

 the Guadalui^e. It differs in its habits from the 8. spinosus, being ex- 

 clusively a dweller in rocks. It may be seen at any time running over 

 the limestone cliffs of the plateau region, to which its light colors present 

 but little contrast. The relation between its color and habitat is quite 

 as striking as in the 8. spinosus. 



Phrynosoma cornutum Harl. The "horned toad" of Texas is found 

 throughout the cretaceous region, commencing at Dallas, and extending, 

 via Austin, to San Antonio. It is abundant at and between these points, 

 on the first plateau region, to the neighborhood of Fort Concho. Its 

 range, according to Baird, extends west to the Eio Grande, and south to 

 Bui. 17 2 



