30 PROCEEDINGS OF THE ACADEMY OF [Jan., 



westward, the valleys of southern New Mexico being respectively the 

 western and eastern limit of range of the two groups. 



Of the species which, according to Cope, range over the first plateau 

 region of Texas (Lower Sonoran) may be mentioned : 



Sceloporus torquatus poinsetti, Holbrookia texana, 



?Sceloponis consobrinus, Salvadora grahaniicc, 



Anota modesta, Crotalus adamanteus atrox, 



Phrynosoma cornutum, Crotalus confluentus. 



The species of the more western desert region are : 



Cnemidophorus tessellatus, Crotaphytes unslizenii, 



iCnemidophorus gularis, Uta stanshunjiana, 



Sceloporus clarkii, Pityophis sayi bcUona. 

 Crotaphytes c. baileyi, 



Of course, the distribution of some of these species has not been 

 worked out in sufficient detail to warrant positive statements as to their 

 range, while a number of recorded localities are so obviously erroneous 

 that we are forced to attribute them to confusion of labels, an accident 

 which could easily happen in the early days of collecting. However, 

 the geographic relationship of the species contained in the present col- 

 lection would seem to be about as alcove. 



To add to the value of the following list we have added notes on the 

 species contained in a valuable collection from Pecos, Tex., recently 

 presented to the Academy by Mr. Arthur Erwin Brown. This region 

 being very similar in its faunal relations to the vicinity of Alamogordo, 

 the comparison of the faunae is of much interest. 



Crotaphytes collaris baileyi (Siejn.). 



Two specimens secured in Dry Canon, May 10 and 13. Dr. Stejneger has 

 divided the old C. collaris into two very closely related forms, C. baileyi 

 of the western deserts and true C. collaris of the eastern region (Texas). 

 In Prof. Cope's paper on the geographic position of Texas, he describes 

 this species as ranging over what we now know as the Lower Sonoran 

 area of that State, while according to Dr. Merriam C. baileyi in the west- 

 ern deserts is an Upper Sonoran form. It w^ould be interesting to know 

 the exact zonal relationship of the specimens described by Prof. Cope 

 from western Texas and New Mexico, where he states that both forms 

 occur together and exhibit all stages of intergradation,so far as arrange- 

 ment of scales is concerned (Crocodilians, Lizards and Snakes of North 

 America). A series of eleven specimens in Mr. A. E. Brown's collection 



