CHAPTER 7 



Reptiles of the Region 



Cold-blooded vertebrates are most numerous both 

 as regards species and individuals in warm climates. 

 Both Lower and Upper Austral zones are rich in rep- 

 tilian life, and the cave region, combining the faunas 

 of both of these zones, is especially so. Most of my 

 work at the cave was too early for successful collecting, 

 and the available notes are few, but the region is known 

 to be of special interest to the student of herpetology. 



SNAKES 



The only known poisonous reptiles are rattlesnakes, 

 of which three, and possibly five, species occur. The 

 large western diamond-backed rattlesnake (Crotalus 

 atrox) (Fig. 59) is found in the valley country and up 

 to the vicinity of the great cave, and many of the local 

 residents will tell of " hundreds" seen and killed "last 

 year." Previous to May 2, 1924, all my efforts to 

 find and obtain specimens of these snakes in the Carls- 

 bad region were unsuccessful, although a dozen people 

 were helping me watch for them. On May 2 I found a 

 small young one that had fallen into a cave in Bob 

 Dow's pasture and could not get out, and this was the 

 only rattlesnake I was able to see alive or collect up to 

 the time I left on May 9, although famous rattlesnake 

 dens, gypsum caves, and prairie-dog towns were visited 

 on hot days in search of them. Still later in the season 



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