12 PROCEEDINGS OF THE ACADEMY OF [1883. 



plates are quite different. It gives out a powerful musky odor 

 when excited, which I have not noticed in the typical form of the 

 species. It is quite probable that it is to this variet}^ that 

 the specimens from Arizona should be referred, which I have 

 heretofore placed under C. lucifer} Not having access to the 

 specimens at this time, I cannot determine this point positively. 

 Of those above enumerated, the specimens from Fort Benton, Fort 

 Wingate, from Socorro, and from Texas, belong to the typical 

 G. confluenkis. The others are the C c. lucifer. 

 Crotalus molossus B. and IJ. 



I killed a fine specimen of this species, which I discovered in 

 the act of springing through a bush. When I struck it, it was 

 suspended over a branch, looking at me. It was heavy in its 

 movements, except at the moment of leaping. 



2. Socorro, New Mexico. 



The collection from this region was made by Prof. Frank Snow, 

 of the University of Kansas, at Lawrence. I here express my 

 indebtedness to Prof. Snow for the opportunity of studying it. 

 Phrynosoma modestum Uirard. 

 Phrynosoma cornutum Harl. 

 Phrynosoma douglassi Bell. 

 Crotaphytus collaris Say. 

 Holbrookia texan* Troscb. 

 Holbrookia maculata B. and G. 

 Sceloporus poinsettii B. and G. 

 Uta stansburiana B. and G. 

 Cnemidopborus sexlineatus L. 

 Diadophis regalia Bd. and GirJ. 



The first time this rare species has been found within the limits 

 of the United States. The single specimen obtained differs from 

 the typical one in having eight superior labials, with the eye 

 above the fourth and fifth. As the preorbital labials are very 

 short, variation to seven in all may be anticipated, as is found in 

 the type. This specimen is smaller than the one from Sononi 

 originally described. 

 Basoanium constrictor L. 

 Eutaenia marciana B. and (i. 



The common species of the Rio Grande valley. 



* Proceedings Philada. Academy, 1866, 307. 



