1170 REPORT OF NATIONAL MUSEUM, 1898. 



scales in twenty-three to twenty-seven rows, all keeled except the 

 external three on each side. 



Color light brown, with one row of dark brown spots usually paler 

 edged, on the median line of the back, which are generally longer than 

 wide anteriorly, but soon become transversely oval, and ultimately 

 assume the form of cross-bands. Tail of the same color as the body, 

 with cross-bands of the color of the dorsal spots. Belly unspotted, 

 but with dark shades in some forms. 



Four well-defined subspecies are embraced in this species; they are 

 defined as follows: 



Cephalic scales larger; 4 rows between superciliary plates, 4 rows below orbit; dor- 

 sal spots and cephalic bands light edged; few posterior cross bands .conjinentus 



Cei)halic scales intermediate; 6 rows between superciliaries; 3 rows below orbit 

 (probably sometimes 4) ; dorsal spots square, with the head bands, not light edged ; 

 posterior cross bands more numerous ; color dotted with brown specks . .pulverulentus 



Cephalic scales smallest; 8 rows between superciliaries; 4 rows below orbit; dorsal 

 si^ots with light centers and l)rown borders light-edged or not ; head bands obsolete ; 

 numerous posterior cross bands leconlel 



Head scales small as in C. c. leconiei ; colors dark ; dorsal spots and bands not pale, 

 centered and closer together than in C. c. leconiei; head wide, rounded lucifer 



The distribution of these subspecies is as follows : The typical one 

 inhabits the plains including western Texas and southern California, 

 also C. c. leconiei belongs to the Great Basin. The C. c. pulverulentus 

 is a form of the Sonoran district; while the C. c. lucifer inhabits the 

 Pacific district to its eastern limit, the northern Kocky Mountains. 



CROTALUS CONFLUENTUS CONFLUENTUS Say. 



Crotalus confluentus confluentus Cope, Proc. U. S. Nat. Mus., XIV, 1892, p. 692. 



Crotalus confiuentus Say, Long's Exped. Rocky Mts., II, 1823, p. 48. — Baird and 

 GiRARD, Cat. N. Amer. Rept., Pt. 1, Serp., 1853, p. 8.— Baird, U. S. Pacific R. R. 

 Surv. Rept., Whipple's Rept., p. 40; U. S. and Mex. Bound. Surv., Reptiles, 

 18.59, p. 14.— Cooper and Suckley, Nat. Hist. Wash. Ter., 1859, p. 295.— Cope, 

 Proc. Acad. Nat. Sci. Phila., 1883, p. 11. 



Figures, Sitgreaves's Exped. Colorado and Zuni, pi. xviii (poor figure); U. S. 

 Pac. R. R. Surv. Rept., Keptiles, pi. xxiv, fig. 4 ; Williamson's Rept. Reptiles, 

 pi. III. — CooPKR and Suckley, Nat. Hist. Wash. Ter. , pi. xii. 



Plates on top of head squamiform, irregular, angulated, and imbri- 

 cated; scales between superciliaries small, numerous, uniform. Four 

 rows of scales between the suborbital series (which only extends to the 

 center of the orbit) and the labials. Labials fifteen or eighteen, nearly 

 uniform. Dorsal series twenty-seven to twenty-nine. Dorsal blotches 

 quadrate, concave before and behind; intervals greater behind. Spots 

 transversely quadrate posteriorly, ultimately becoming ten or twelve 

 half rings. Two transverse lines on superciliaries, inclosing about one- 

 third. Stripe from superciliary to angle of jaws, crosses angle of the 

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



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 



