AGKISTRODON. 17 



he 



Genus AGKll^^TRODOIV, Beauv. 



Gen. Char. A deep pit between nostril and the eye. Nine 



plates on top of head. Without rattle. Poison fangs as in Crotalus. 



One pair of occipitals. A loral between the nasal and anterior orbit- 



als. Labials excluded from the orbit by the presence of suborbital 



plates. Scales carinated; rows 23 in number. Subcaudal scutellae 



divided posteriorly. Sometimes a small plate between the vertical 



and postfrontals. Habits terrestrial. 



Stn. Agkistrodon, Pal. de Beauv. Trans. Amer. Phil. Soc. Philad. IV, 

 1799, 381. 



1. Ag'kisfrodon coBilorfrix, B. & G. — Loral present. Labials 

 not entering into the orbit. Dorsal rows of scales 23. Color light chestnut, 

 with inverted Y'Shaped darker blotches on the sides. Labials yellowish 

 white. 



Stn. Boa contortriz, Linn. Syst. Nat. I, 273. — Gm. L. Syst. Nat. ed. xiii, 

 I, iii, 1788, 1082, 



Agkistrodon mokason, Beauv. Txans. Amer. Philos. Soc. Philad. IV, 

 1799, 380. 



Scy talus cupreus, Rafin. Amer. Journ. Sc. I., 85. — Harl. Med. & Phys. 

 Res. 1835, 130. 



Trigonocephalus cenchris, ScHL. Ess. Phys. Serp. Part, desc, 1837, 553. 

 PI. XX, fig. 10 and 11. 



Trigonocephalus contortriz, Holbr. N. Amer. Herp. II, 1838, 69 PL xiv, and 

 2d ed. Ill, 1842, 39. PL viii. 



Copperhead. 



More slender than ToxicopMs pisciovorus. Plates on neck and side 

 smaller. Two anterior orbitals, one above the other, the lower nar- 

 rower, and forming the posterior wall of the pit. A distinct loral 

 between these and the posterior nasal. Labial not forming part of 

 the orbit, but separated by the four post and suborbitals. Labials 

 not so largely developed ; 8 above, 3d and 4th largest ; 9 below. 



Above light hazel brown, rather brighter on the top of the head, 

 and everywhere minutely mottled with very fine dark points. On 

 each side is a series of 15-26 darker chestnut-colored blotches resting 

 on the abdominal scutella;, and suddenly contracting about the mid- 

 dle of the side, so as somewhat to resemble an inverted Y- These 



^OC. i>v 



lYb 



