8 CROTALUS. 



lated. In C. lucifcr, the line on the side of the head, instead of 

 going directly from the posterior end of the superciliary to the com- 

 missures, passes back nearly parallel to the mouth, crossing along the 

 4th row of scales above the labial. The second line in front of the 

 eye is much wider below in C. lucifer, and the face generally shows 

 more of white, while the dark portions are much darker. 



A specimen collected in California by Dr. Leconte resembles this, 

 but owing to the imperfect state of preservation, little definite can be 

 ascertained. The dorsal figures are, however, more in lozenges than 

 in hexagons. Color dark. Size, very large. 



Oregon. 168. 25. 25. 27f . 3|. (in dep.) Expl. Esped. 



5. Crotalus COllfluentus, Sat. Head subtriangular. Plates on 

 top of head squamiform, irregular, angulated, and imbricated ; scales be- 

 tween superciliaries small, numerous, uniform. Four rows of scales be- 

 tween the suborbital series (which only extends to the centre of the 

 orbit) and the labials. Labials 15 or 18, nearly uniform. Dorsal series 

 27-29. Dorsal blotches quadrate, concave before and behind ; intervals 

 greater behind. Spots transversely quadrate posteriorly, ultimately becom- 

 ing 10 or 12 half rings. Two transverse lines on superciliaries, enclosing 

 about one-third. Stripe from superciliary to angle of jaws, crosses angle of 

 the mouth on the second row above labial. Rostral margined with lighter. 



Stn. Crotalus confluentus, Sat, in Zow^'s Exped. Rocky Mts. II, 1823, 48. 

 C. Lecontei, Hallow. Proc. Acad. Nat. Sc. Philad. VI, 1851, 180. 



This species bears a considerable resemblance to C. atrox, but the 

 body is more slender and compact. Scales on the top of the head 

 anterior to the superciliaries nearly uniform in size. Line of scales 

 across from one nostril to the other consists of six, not four as in C. 

 atrox. Superciliaries more prominent. Labial series much smaller. 

 Upper anterior orbitals much smaller, as also is the anterior nasal. 

 Scales on the top of the head less carinated. Scales between super- 

 ciliaries smaller and more numerous, five or six in number instead of 

 four. Two lateral rows of scales smooth, first, second, and third 

 gradually increasing in size. Scales more linear than in C. atrox. 



General color yellowish brown with a series of subquadrate dark 

 blotches, with the corners rounded and the anterior and posterior 

 sides frequently concave, the exterior convex. These blotches are 

 ten or eleven scales wide and four or five long, lighter in the centre, 

 and margined for one-third of a scale with light yellowish. The inter- 

 vals along the back light brown, darker than the margins of the 



