79. HETERODON. 15d 
Coluber heterodon, Harlan, Phys. Med. Res. p. 120 (1885). 
thraso, Harl. 1. ¢. 
Heterodon niger, Troost, Ann. Lye. N. York, iii. 1836, p. 186; 
Holbr. l. e. p. 63, pl. xvi.; Baird § Gir. Cat. p. 55; Dum. § Bibr. 
vi. p. 769; Giinth, Cat. p. 83. 
annulatus, Troost, J. c. p. 188. 
—— tigrinus, Troost, /. c. p. 189. 
cognatus, Baird § Gir. l. c. p. 54; Garm. Bull. Essex Inst. 
xxiv. 1892, p. 106. 
atmodes, Baird § Gir. l. ¢. p. 57. 
Maxillary teeth 9 to 11+2. Rostral considerably narrower than 
the distance between the eyes; an azygous shield separating the 
internasals ; prefrontals usually in contact with each other ; frontal 
longer than broad, shorter than its distance from the end of the 
snout, as long as the parietals; loreal deeper than long; eye 
surrounded by 10 or 11 shields in addition to the supraocular ; 
temporals small, scale-like ; seven or eight upper labials ; one pair 
of chin-shields, in contact with three lower labials.. Scales strongly 
keeled, of outer row smooth, in 23 to 27 rows. Ventrals 120-150 ; 
anal divided; subcaudals 37-60. 
Total length 800 millim. ; tail 130. 
United States, east of the Rocky Mountains. 
A. Brown or red above, with a dorsal series of large square or 
transverse dark brown or black spots, separated from each 
other by light interspaces, and a lateral alternating series of 
smaller spots ; an elongate black blotch or band on each side 
of the head, sometimes extending forwards to the frontal, a 
transverse dark band between the eyes, and an oblique one 
from the eye to the angle of the mouth; belly yellowish or 
reddish, clouded with brown. 
a,b. 3 (Se. 25; V. 127; Bloomington, C. H. Bollman, “Esq. 
C. 50) & yg. (Sc. 25; Indiana. [C.]. 
V. 128; C. 53). 
e. 6 (Se. 25; V. 127; Pennsylvania. Smithsonian Instit. 
C. 52). eAth 
d. Yg. (Sc. 23; V. 120; Charleston. 
C. 52). 
e. Yg. (Sc. 25; V. 128; S. Carolina. Smithsonian Instit. 
C. 49). [P.]. (As typical of 
HT. atmodes.) 
f-h, i. 3 (Se. 25; V.129, Duval Co., Texas. W. Taylor, Esq. (C.}. 
130; C. 48, 48), 2 (Se 
25; V..184; C. 37), & 
C. 48) 
k. Q (Se. 25; V. 141; Texas. 
C. 44). | 
» 1, Skeleton. N. America. 
m. Skull. N. America. 
