REPTILES AND AMPHIBIANS OF TEXAS 41 



in every respect with the type, I shall here recognize 

 it as a distinct species. 



125. Heterodon PliATYRHiNUS Latreille. Spreading Adder: 



Hog-nosed Snake. 



The "bloving adder" is distributed over the entire 

 eastern ani middle sections west to the foot of the 

 plains and south almost to the Rio Grande River. 

 This specis follows the canyons in the Panhandle 

 and by thii means penetrates the plains region for a 

 short distace. 



126. Heterodon nascius Baird and Girard. Western 



Spreaiing Adder. 

 Western Texas, extending eastward in the Rio 

 Grande V ley as far as Cameron County. Common 

 in the tris-Pecos counties and in the Panhandle 

 west of tfe foot of the plains. In the Rio Grande 

 Valley thl species seems to be found only in the 

 border coUies and does not range northward into 

 the interiqfor any distance. 



127. SiBON septiItrionalis Kennicott. Ringed Snake. .' 



This B,nCyhe following species are tropical sn-akes 

 which exte\ their range into North America f^nly in 

 the extreni southern portion of Cameron County, 

 Texas. Sih septentrionalis has been captured st 

 BrownsvillQn several occasions. 



128. Erythrolam^js imperialis Baird. Imperial Snake. 



Brownsvil\ Texas. 

 \ 



129. Tantilla NIGI^ps Kennicott. Black-headed Tantilla. 



Western argouthern Texas. Recorded from San 

 Antonio and \i Diego by Cope and from Pecos by 

 Brown. CopGays that it is common between the 

 upper waters tthe Brazos and Colorado Rivers. I 

 did not find it any of the localities visited by me. 



130. Tantilla GRACihBaird and Girard. Graceful Tan- 

 tilla. 

 TexaS; west t^e foot of the plains, south to the 



