Reptiles and Amphibians of Illinois. 315 



Ancistrodon piscivorus, Lac. Water Moccasin. 



Crotalus piscivorus, Lac, Buffon's Hist. Nat.. Quad. Ovip. et 



Serpens. 1789, II., pp. 130, 424. 

 Trigonocephalus piscivorus, Holbr., N. A. Herp., 1842, III., p. 33, 



pi. 7. 

 To.ricopJiis j^iscivorns, Bd. and Gir., Cat. M. A. Kept., Pt. I., 



1853, p. 19. 

 Trigonocephalus 2nsciiy>rt(s, Dum. et Bibr., Erp, Gen., VII,, Pt. 



2. 1854, p. 1491. 

 Ancistrodon piseivorns, Cope, Proc Acad. Nat. 8ci. Phila., 1859, 



p. 336. 

 Ancistrodon piseivorns, subsp. piscivorus, Davis and Rice, Bull. 



111. State Lab. Nat. Hist., I., No. 5, 1883, p. 28; Bull. Chicago 



Acad. Sci., 1883. 

 Ancistrodon piscivorus, S. Garman, Mem. Mus. Comp. Zool., 



1883, p. 121, pi. 8, fig. 2. 



Body short and stout, tapering toward both extremities. 

 Head large, deep, wide. Neck slender. Tail short, compressed, 

 tapering, abruptly more slender than the body. All the dorsal 

 scales carinate. Rostral plate large, truncate above. Inter- 

 nasals triangular, the outer margin arcuate. Frontal large, 

 longer than wide, hexagonal. Parietals large, their posterior 

 extremities nearly or quite separated by transverse sutures. 

 Nasals two. No loreal. Three anteorbitals, the superior large, 

 elongate, and reaching the posterior nasal. Three small post- 

 orbitals. Seven or eight supralabials, the third reaching the 

 orbit Ten infralabials. Dorsals in twenty-five rows. Ven- 

 trals 136 Subcaudals about 45, often the first, and generally 

 from iit«^f^i to twenty-five posterior, paired. 



Color above brown or blackish, with about eleven trans- 

 verse black bands alternating with as many brown bands, the 

 latter widening on the back and with a dusky center, the black 

 bands widening at the sides and often with a brown area in the 

 expanded lateral portions. Sometimes nearly uniform blackish 

 brown, often mostly brown with narrow transverse lines of 

 black. With numerous black blotches beneath, black pos- 

 teriorly. Head uniform brown or black above, with a wide 

 black band, edged above with brown and below with yellow, 

 extending from the eye over the angle of the mouth and ter- 

 minating on the neck. Tail uniform black, or with a few pale 

 spots beneath posteriorly, sometimes banded. 



