106 PROCEEDINGS OF THE ACADEMY OF [Jan., 



long) would also show these lines more sharply defined than they 

 would become later in life. The transverse light line on the supra- 

 oculars is precisely as in lucifer. 



This species comes very near to confluentus, but, on account of 

 the constancy of the slight differences, I am obliged to give it 

 specific rank; the head scales are rather smaller, the rows between 

 supraoculars numbering in six examples 4, 5, 8, 8, 8, 9; between 

 suboculars and labials 2-4; scales in 25-27 rows; ventrals 165- 

 189; subcaudals 18-26. Size about the same as co?i/?ite?iiu.s. The 

 pattern is closely similar, but the dark oblique streak behind the 

 eye always begins posterior to its centre and runs backward directly 

 to the angle of the mouth, not curving downward as sharply as in 

 confluentus; the light lines bordering it are wider; the transverse 

 light line on supraoculars is present; the belly is yellow or green- 

 ish, with the posterior border of each ventral lighter. In some 

 specimens the general color is dark, approaching even to black. 



Hab. — The Pacific coast; California to British Columbia, Idaho 



and northern Nevada and Utah. 



Crotalus horridus L. 



Syst. Nat., Ed. X, 214; C. dunssus B. and G., I. c, 1 ; C. horridus 

 Cope, 7. c, 693, and Eep. Nat. Mus., 1185; Boul., I. c, III, 578 ; Stej. 

 I. c, 426. 



Size smaller and body more slender than in adamanteus ; rostral 

 high; two I'ows of small plates behind nasals; 4-8 scales between 

 supraoculars; 2-4 between suborbitals and labials; usually but one 

 plate on canthus; scales in 23-25 rows (occ. 27); ventrals 165- 

 178; subcaudals 18-25. 



Average specimens are about 900 to 1,000 mm. long, and it is 

 doubtful if the species ever much exceeds 1,400. 



Tlie body color is variable — sulphur yellow, ashy and almost 

 black (one specimen from Alabama was in life a peculiar pale 

 drab), crossed by twenty or more irregular chevron-shaped black 

 bauds; the bauds are sometimes complete, but often broken into 

 angular spots on the sides, but they always have a ragged or zigzag 

 appeai'ance. The tail is black; belly yellow marked with dusky; 

 head dark, without distinct markings. 



Hab. — New England to northern Florida; west to Iowa, Okla- 

 homa and northern Texas. 



