APPENDIX F. REPTILES. , 189 



Stn. — Crotalus confluentus, Say, in Long's Exped. Rocky Mts. II, 



1823, 48. B. & G. Cat. N; Amer. Kept. I, 1853, 8. 

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



Description. — 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 

 superciliaries 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 (7, 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 mar- 

 gined for one-third of a scale with light yellowish. The intervals along 

 the back light brown, darker than the margins of the blotches. Ante- 

 riorly the interval between the dark spots is but a single scale ; poste- 

 riorly it is more, becoming sometimes two scales ; where also the spots 

 are more rhomboidal or lozenge-shaped ; nearer the tail, however, they 

 become transversely quadrate. The fundamental theory of coloration 

 might be likened to that of Crotalus adamanteus, viz : of forty or fifty 

 light lines decussating each other from opposite sides ; but the angles 

 of decussation, instead of being acute, are' obtuse, and truncated or 

 rounded off throughout. Along the third, fourth, and fifth lateral 

 rows of scales is a series of indistinct brown blotches covering a space 

 of about four scales, and falling opposite to the dorsal blotches : be- 

 tween these blotches, and opposite to the intervals of the dorsal blotches, 

 are others less distinct. Along the fifth, sixth, seventh, and eighth 

 rows is a second series of obsolete blotches, each covering a space of 

 about four scales, and just opposite the intervals between the dorsal 

 spots. The dorsal and lower series are separated by an interval of 

 three scales, this interval light brown. Beneath, the color is dull yel- 

 lowish, and ten or twelve darker half rings are visible on the tail. 



In point of coloration the principal features, as compared with C 

 atrov, lie in the disposition of the dorsal blotches in subquadrate spots 

 instead of subrhomboids ; the intervals thus forming bands across the 

 back perpendicular to the longitudinal axis. This tendency to assume 



