SYNOPSIS OF GENERA ANB SPECIES 



OP 



NEW-YORK SERPENTS. 



Genus CROTALUS, Linn. 



Gen. Char. Upper surface of head covered witli small plates, scale-like, 

 with a few larger ones in front. The tail is terminated by a well deve- 

 loped rattle. A deep pit between the eyes and the nostrils. Subcaudal 

 scutellae entire. Temporal and labial shields small and convex. 



1. Crotalus durISSUS*, L. — Rattlesnake. 



Spec. Char. Head angular. Scales between the snperciliaries small, numerous, 

 uniform. Plates above snout, 2 anterior frontal, and 6 postfrontal. Suborbital 

 chain continuous, of large scales : two rows between this and labials. Labials 

 12 - 14 above, fifth largest; 13 - 15 below. Rows of scales on the back 23 - 25, 

 all carinated : carination on outer row obsolete. Tail black. Above sulphur- 

 brown, with 2 rows of confluent brown lozenges. Light line from superciliary to 

 angle of the mouth: behind this a dark patch. 166, 25, 23, 42, 5 (Pennsylvania). 



SYNONYMS. 



Crotalus durissus, LiNN. Syst. Xat. I. 1766, 372.— Gm. Linn. Syst. Nat. ed. xiii. 

 I. iii. 1788, 1081.— HoLBR. N. Amer. Herp. III. 1842, 9. Pl.i.— Dekay, 

 N. Y. Fauna, Pt. III. 1842, 55. PI. ix. fig. 19.— Storer, Rep. Rept. ofMass. 

 1839, 233.— Baird & Girard, Catal. N. Am. Serpents, 1853, 1. 



Vipera caiidisona americana, Catesb. Nat Hist. Carol. II. 1743, 41. PI. Ixi. 



Northern Rattlesnake. 



The Crotalus durissus, or northern rattlesnake, is more extensively dis" 

 tributed throughout the United States than any other of the genus. It is 



* Tlie numbers preceding the specific name are the same with ihe corresponding figures on the plates. 



