HETERODON SIMUS. 61 



synonymous with his Boa contortrix I cannot determine, for the only thing they 

 have in common more than any other snake is their geographical distribution, and 

 this in fact only applies to some of the southern states, for the Boa (Trigonoce- 

 phalus) contortrix has a wide range, while that of the Heterodon simus is 

 hmited. 



