33 



TRIGONOCEPHALUS .—OppcL 



Genus Trigonocephalus. — Characters. Head large, triangular, covered with 

 plates in front, and on the vertex to behind the orbits, and with scales posteriorly; 

 a deep pit between the eyes and nostrils; upper jaw armed with poisonous fangs; 

 body thick; plates on the abdomen and base of the tail; a few scales at the apex. 



TRIGONOCEPHALUS Vl^CW ORV^.—Ladpcde. 



Plate VII. 



Characters. Head very large, triangular, covered with plates in front, and on 

 the vertex, and with scales behind; a deep pit between the eye and nostril; upper 

 jaw armed with poisonous fangs; body thick, dusky greenish-brown, tinged with 

 yellow, and with transverse bands of black. PI. 130. Caud. PI. 29. Sc. 4. PI. 

 2.* Sc. 8. 



Synonymes. Water viper, Catesby, Carol., vol. ii. p. 43, pi. xliii. 



Crotalus piscivorus, LacepMe, Hist, des Serp., torn. ii. p. 424. 



Scy talus piscivorus, LatreiUe, Hist, des Rept, torn. iii. p. 163. 



Scytale piscivorus, Daudin, Hist. Nat. des Rept., torn. v. p. 344. 



Coluber aquaticus, Shaiv, Gen. Zool., vol. iii. p. 425, pi. iii. 



Natrix piscivorus, Merrem, Versuch eines Syst. der Amphib., p. 131. 



Trigonocephalus tisiphone, Cuvier, Reg. An., vol. ii. p. 89. 

 ^ Scytalus piscivorus, Harlan, Med. and Phys. Res., p. 129. 



Toxicophis leucostomus, Troost, Ann. Lye. Nat. Hist. N. Y., vol. iii. p. 176. 



Water Moccasin, Viilgo. Cotton Mouth, in the western country. 

 Vol. hi.— 5 



