79. HETERODON. 155 



Coluber heterodon, Harlan, Phys. Med. Res. p. 120 (1835). 



tliraso, Harl. I. c. 



Heterodon niger. Troost, Ann. Lye. N. Yofk, iii. 1836, p. 186; 



Holbr. I. c. p. 63, pi. xvi. ; Bnird i^- Gir. Cut. p. 55 ; Dum. •i)- Bibr. 



vii. p. 769 ; Giinth. Cut. p. 83. 



aunulatus, Troost, I. c. p. 188. 



tip:rinus, Troost, I. c. p. 189. 



cog-natus, Baird ^ Gir. I. c. p. 54 ; Garni. Bull. Essex Inst. 



xxiv. 189i>, p. 106. 

 atmodes, Baird S)- Gir. I. c. p. 57. 



Maxillary teeth 9 to 11 + 2. Eostral considerably narrower than 

 the distance between the eyes ; an azygous shield separating the 

 internasals ; praefroutals usually in contact with each other ; frontal 

 longer than broad, shorter than its distance from the end of the 

 snout, as long as the parictals ; 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. Yentrals liiO-15U ; 

 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. d' (Sc. 25 ; V. 127 ; Bloomington, C. H. BoUman, Esq. 



C. 50) & yg. (Sc. 25; Indiana. [C.]. 



V. 128; C. 53). 



c. c? (Sc. 25 ; V. 127 ; Pennsylvania. Smithsonian Instit. 

 C. 52). [P.]. 



d. Yg. (Sc. 23; V. 120; Charleston. 

 C. 52). 



e. Yg. (Sc. 25 ; Y. 128 ; S. Carolina. Smithsonian Instit. 

 C.^19j. [P.]- (As typical of 



H. atmodes.) 

 f-h, i. S (Sc. 25 ; V. 129, Duval Co., Texas. A^'. Taylor, Esq. [C.]. 



J 30; C. 48,48), $ (Sc. 



25; V. 134; C. 37), & 



yg. (Sc. 25; V. 128; 



C. 48). 

 k. 2 (Sc. 25 ; V. 141 ; Texas. 



C. 44). 

 /. Skeleton, N. America. 



in. Skull. N. America. 



