10. ANCrsTSODON. 519 



10. ANCISTRODON. 



Agkistrodon, Palisot de Beauvois, Tr. Am. Philos. Soc. iv. 1799, 

 p. 381 ; Baird §• Gir. Cat. N. Am. Rept. p. 17 (1853) ; Stejneger, 



Rep. U.S. Nat. Mus.f. 1893, p. 401 (1895). 

 Scytale, part., Latr. Hist. Rept. iii. p. 158 (1802) ; Daud. Hist. 



Rept. V. p. 334 (1803). 

 Cenchris, Daud. t. c. p. 356 ; Wagl. Syst. Amph. p. 175 (1830) ; 



Gray, Zool. Misc. p. 50 (1842), and Cat. Sn. p. 15 (1849). 

 Oophias, part., Merr. Tent. Sgxt. Amph. p. 154 (1820). 

 Trigonocephalus {non 0pp.), Kuhl, Isis, 1822, p. 473 ; Fitting. N. 



Classif. Rept. p. 34 (1826) ; Wagl. I. c.p. 173 ; Gray, II. ce. pp. 50 



& 14 ; Dam. <f Bibr. Erp. Gin. vii. p. 1488 (1854) ; Jan, Mmco 



sist. Ofid. p. 124 (1883) ; Strauch, ScU. Russ. R. p. 232 (1873). 

 Tisiphone, Fitzing. I. c. ; Peters, Mon. Berl. Ac. 1862, p. 673. 

 Acontias {non Cm.), Troost, Ann. Lye. N. York, iii. 1836, p. 176. 

 Toxicophis, Troost, I. a. p. 190 ; Baird 8; Gir. I. c. p. 19. 

 Trigonoeephalus, part., Schleg. Phys. Serp. ii. p. 527 (1837). 

 Halya, Gray, Cat. p. 14 ; Peters, I. c. p. 671 ; Giinth. Rept. Brit. 



Ind. p. 392 (1864). 

 Hypnale, Grayy I. c. p. 15 ; Peters, I. c. p. 673 ; Giinth. I. c. p. 394. 

 Leiolepis (non Cuv.), Dum. 8^ Bibr. M4m. Ac. Sc. xxiii. 1853, p. 534, 



and Erp. G4n. vii. p. 1499. 

 Ancistrodon, Baird, Serp. N. York, p. 13 (1854) ; Cope, Proc. Ac. 



Philad. 1859, p. 336 ; Peters, I. c. p. 671 ; Bouleng. Faun. Ind., 



Rept. p. 423 (1890) ; W. E. Taylor, Amer. Nat. 1895, p. 283. 

 Oalloselaama, Cope, Proc. Ac. Philad. 1859, p. 336 ; Giinth. I. c. 



p. 391. 



Upper surface of head with the nine normal shields, or internasals 

 and preefrontals broken up into scales. Body cylindrical ; scales 

 smooth or keeled, with apical pits. Tail moderate or short ; sub- 

 caudals single or in two rows. 



Borders of the Caspian Sea ; Asia ; North and Central America. 



Synopsis of the Species. 



I. Scales in 21-27 rows ; internasals and prsefrontals well deve- 

 loped. 



A. Scales keeled. 



1. Anterior subcaudals single; second upper labial usually 

 forming the anterior border of the loreal pit. 



a. Snout not produced. 



No loreal, upper prseocular in contact 



with the posterior nasal ; third upper 



labial usually entering the eye ; scales 



in 25 (rarely 27) rows ; ventrals 130- 



147 ; subcaudals 33-51 1. piscivorus, p. 520. 



A loreal, separating the upper prseocular 



from the posterior nasal ; eye separated 



