774 



REPORT OF NATIONAL MUSEUM, 1898. 



The two outer dorsal rows are both perfectly smooth; in H. n. nasicus 

 the second is distinctly though delicately carinate. 



The ground color is light yellowish grey, with a dorsal series of rather 

 indistinct subquadrate or rounded blotches, two to two and a half scales 

 long, and separated by intervals of one or two scales, rather wider 

 anteriorly. Below this is a series of very distinct purplish black circu- 

 lar blotches, covering four scales transversely and two longitudinally; 

 below this one or more indistinct series of spots. This pattern of col- 

 oration is very similar to that of H. n. nasicus^ but the ground color is 

 always lighter and less distinct. The ujjper lateral series is of a pur- 

 plish black, and much more distinct, forming a prominent character. 



Abdomen nearly entirely black, except a few yellow scuta. The head 

 is marked as in H. n. nasicus except that the nasals, prefrontals, and ros- 

 tral are all yellowish, while in the latter species they are dark in front 

 of the light transverse line which crosses the crown behind the rostral; 

 and in H. n. Tcennerlyi the light line across the superciliaries and vertical 

 is much broader than in H. n. nasicus. This species differs from H. n. 

 simus in many of the same features as does H, n. nasicus. These, together 

 with the small or absent loreal and small number of supplemental plates, 

 readily distinguish it. 



Heterodon nasicus kennerlyi Kennicott. 



Catalogue 

 No. 



1282 



7290 

 5185 

 8878 

 8413 

 10202 



Number 

 of speci- 

 mens. 



Locality. 



Matamoras, Mexico. 



Lower Eio Grande 



Port Stockton, Texas 



Southern Arizona 



....do 



White Elver Cafion, Ari- 

 zona. 



When 

 collected. 



— , 1873 



Oct. — , 1874 



— , 1879 



Prom whom received. 



Lieutenant Conch, U.S. A. 



A. Schott 



Patrick Dufify 



H. W. Henshaw 



...do 



Dr.K.T.Burr 



Nature of 

 specimen. 



Alcoholic 

 type. 

 do. 

 do. 

 do. 

 do. 

 do. 



HETERODON NASICUS NASICUS Baird and Girard. 



Heterodon nasicus Baird aud Gikard, Cat. N. Amer. Rept., Pt. 1, Serps., 1853, 



p. 61. — Jan, Icon. Gen. Ophid., Pt. 10, pi. v, fig. 1. 

 Heterodon simus nasicus Cope, Check-list N. Amer. Batr. Rept., 1875, p. 43. 



Frontal broader than long. Rostral excessively broad aud high. 

 Azygous plate surrounded behind and on the sides by many small plates 

 (9-24). A second loreal. Labials short and excessively high. Dorsal 

 rows of scales twenty-three, exterior alone smooth. A dorsal series of 

 about titty blotches, with four or five others on each side. Body beneath 

 black. A narrow white line across the middle of the superciliaries; a 

 second behind the rostral. A broad dark patch from the eye to the 

 angle of the mouth, crossing the last two labials. 



Frontal plate very broad, subhexagonal. Parietals short. Rostral 

 very broad, high, more than in the other species, outline rounded. The 

 interval between the opposite frontals, the rostral, and the frontal 

 occupied by a number of small plates, from nine to twenty-five, arranged 



