Cope.] ^82 [N ov. 20, 



limb from groin, .0415 ; do. of posterior foot, .019 ; of tarsus, .0095 ; of 

 tibia, .0145. Width of head at anterior border of tympana, .008. 



Rich cream-color on all the upper surfaces, on one specimen tinged with 

 brown. Below lighter cream-color. A pale brown band with a narrow 

 yellow superior margin from the end of the muzzle to the groin. The 

 brown tint fades out rapidly below, and on the posterior half of the side is 

 reduced to a narrow line. A narrow brown band on each side of the back, 

 which extend as far forward as the orbit. 



This species is well characterized, having little resemblance to any other 

 member of the genus. It was taken along a mountain stream in the 

 department of Chiriqui. Two specimens ; No. 13473. 



IV. City op Chihuahua, Wilkinson. 



Information as to the character of the reptilian fauna of the central part 

 of the State of Chihuahua, has been a desideratum. A few specimens 

 from the region were sent many years ago to the Museum of the Smithso- 

 nian Institution by Mr. John Potts, and are recorded in the report of the 

 Mexican Boundary Survey by Professor Baird. A collection from the 

 southern part of the Sierra Madre in this State, from the mining district of 

 Batopilas, was sent me for study by Mr. Wilkinson, and was reported on 

 in the Proceedings of this Society for 1879, p. 201. That region is how- 

 ever much to the south of the one represented by the present collection, 

 and is much more elevated. 



The great plain in which the city of Chihuahua stands is arid, and the 

 vegetation is generally sparse. Low mountains bound it on the east and 

 west. The formation of the surface of the plain is a coarse drift composed 

 principally of little or much rounded fragments of basalt, more or less 

 cemented together by a calcareous mud. The same formation composes 

 the plains of Southern New Mexico. The vegetation of this plain consists 

 of mesquit, Fouquieria, Yuccas and Opuntias. South of the city is a 

 considerable tract of grassy country. The city stands on a creek, whose 

 waters are used by the inhabitants for supporting a cultivation which 

 produces a most agreeable contrast to the general aspect of the country. 



Mr. Wilkinson's collection indicates that reptiles are numerous, since 

 he obtained, in a short time, 471 individuals. These only represent twenty- 

 six species and subspecies. They are as follows. 



Lacertilia. 



1. Phrynosoma cornutum Harl. Abundant ; Nos. 14228-52-90, 14300. 



2. Phrynosoma modestum Gird. Abundant ; Nos. 14229-51-91 ; 14301. 



3. Holbrookia texana Trosch. Abundant. Nos. 14234-38-43-47, 



14309. 



4. Holbrookia maculata B. & G. Abundant. Nos. 14239-40-45, 



14310. 



5. Crotaphytus collaris Say. Moderately abundant. Nos. 14300-7. 



