OPB1DIA COLUBEIDAE HETEEODON SIMUS NAS1CUS. 555 



above, with only a trace of the lateral band in front, and having a red 



throat. 



EDTAENJA MARCIANA, Baird & Girard. 



Eutaenla marciana, BAIRD & GIRARD, Cat. N. A. Rept., pt. i, Serp., 1853, 36. BD., 

 U. S. & Mex. Bound. Surv., ii, Reptiles, 1855, 17. COPE, Check-List N. A. 

 Batrach. & Rept., 1875, 41. 



HAB. Arkansas, Texas, and entire Rio Grande Valley. 



This beautiful species was found to be exceedingly abundant in the 

 valley of the Rio Grande in New Mexico. When taken, it discharges from 

 the small glands situated near the anus a secretion of a peculiarly unpleas- 

 ant odor, and this fact has also been noticed in regard to all the serpents of 

 this genus. 



Genus HETERODON, Beauvois. 



HETERODON SIMUS, Linn., subspecies NASICUS, Baird & Girard. 



Heterodon nasicus, BAIRD & GIRAKD, Stans. Rep. Exp. Great Salt Lake, 1852, 352. 

 lid., Marcy's Rep. Exp. Red Riv., 1852, 208. lid., Cat. N. A. Rept, pt. i, Serp., 

 1853, 61-157. HALLOW., Sitgreave's Rep. Zuni & Col. Riv., 1853, 147. Id., 

 Proc. Acad. Nat. Sci. Phila., 1856, 249. BD., P. R. R. Rep., x, 1859, 41. 

 Id., U. S. & Mex. Bound. Surv., ii, Rept., 1859, 18. HAYD., Trans. Am. Phil. 

 Soc., xii, 1862, 177. COPE, Proc. Acad. Nat. Scu Phila,, 1866, 307. ALLEN, 

 Proc. Bost. Soc. Nat. Hist., xvii, 1874, 69. 



Heterodon simus LINN., subspecies nasieus, BAIRD & GIRARD, COPE, Check-List N. A. 

 Batrach. & Rept., 1875, 43. 



HAB. Souoran and Central Subregious and Texas. 



-Very common, and greatly dreaded by the settlers in the West, who 

 call them "Sand Vipers", notwithstanding they are entirely harmless. One 

 specimen taken of unusually large size. 



