79. HBIBEODON. 155 



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



thraso, Harl. I. c. 



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



Holbr. I. c. p. 63, pi. xvi. ; Bnird Sr Gir. Cut. p. 55 ; Hum. ^ Bihr. 



vii. p. 769 ; Giiwth. Cat. p. 83. 



annulatus, Troost, I. c. p. 188. 



tigrinua, Troost, I. c. p. 189. 



cognatus, Baird ^ Gir. I. c. p. 64 ; Garm. Bull. Essex Inst, 



xxiv. 1892, p. 106. 

 atmodes, Baird 8/- Gir. I. c. p. 57. 



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

 the distance between the eyes ; an azygous shield separating the 

 internasals ; preefrontals 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 Eocky 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. tS (Sc. 25 ; V. 127 ; Bloomington, C. H. Bollman, Esq. 



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

 V. 128; C. 53). 



c. d' (Sc. 25 ; V. 127 ; Pennsylvania. Smithsonian Instit. 

 0. 52). [P.]. 



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



C. 52). ^ . 



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

 C. 49). [P-]- (^8 typical of 



S. atmodes.) 

 f-h, i. S (So. 26 ; V. 129, Duval Co., Texas. W. Taylor, Esq. [C.]. 



130; C. 48,48), 2 (Sc. 



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



yg. (Sc. 25; V. 128; 



C. 48). 

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



C. 44). 

 I. Skeleton. N. Amenca. . 



m. Skull. N. America. 



