POISONOUS SNAKES OF NORTH AMERICA. 437 



1874. — Crotalus adamanteus, Jan, Icon. Opliicl., livr. 46, pi. ii, fig. 1 (not of 



Beauvois). 

 1875. — Crotalus adamanteus, var. scutulaius, Copk, Bull. U. S. Nat. Mus., No. 1, 

 p. 33.— Cope, Proc. U. S. Nat. Mus. xiv, 1891, p. 690 (1892).— Caudiwua 

 adamantea scutulata, Coues, in Wheeler's Surv. W. 100 Mer., V, p. 607. 

 Figures. — Baird, Mex. Bound. Surv., ir, Rept., pi. i (1859). — Baird, Pac. R. R. 

 Rep., X, Rept., pi. xxiv, fig. 3 (1859).— Jax, Icon. Ophid., livr. 46, pi. ii, fig. 1 

 (1874). 



Description.* — Head subtriangular; plates on head; 2 anterior fron- 

 tals (iuternasals) in contact; between these and superciliaries (snpra- 

 ocnlars), on side of the crown, 2 imbricated phxtes; space inclosed occu- 

 pied by smaller scales; superciliaries (supraoculars) bordered by a row 

 of larger scales; the anterior much largest. Three rows of scales 

 between labials and suborbitals; labials 16 above, first, fifth, and sev- 

 enth, largest; 15 below, first and third largest; dorsal rows 25-27; 2 

 exterior rows smooth ; on the tail 3-0 half riugs. Color yellowish brown, 

 with a continuous succession of dorsal lozenges, sometimes truncate 

 beforeand behind ; intervals all narrow. A single transverse light line ; 

 superciliary stripe from superciliary directly to the angle of the mouth. 



General style of coloration somewhat as in C. adamanteus. Ground 

 color above, dull yellowish brown, with a series of subhexagonal 

 patches from the head nearly to the tail, in an uninterrupted series, 

 separated throughout by narrow lines. We may refer the markings to 

 the intersection of two series of light yellowish lines, about 40 in 

 number, crossing obliquely from each side across to the other, along 

 the anterior half of as many oblique series of scales. The lateral 

 decussation is along the sixth row of dorsal scales; on the back, where 

 they cross, the lines are confluent for a breadth of 5 or G scales, mak- 

 ing a series of transverse lines across the back, truncating the obtuse 

 angles of the rhomboids, which would otherwise be produced. Some- 

 times the acute lateral angles of the rhomboids are also truncated. 

 Laterally, the yellowish lines are more or less obsolete, leaving a more 

 or less distinct chain pattern. The rhomboids or subrhomboids 

 inclosed have a narrow margin of dark brown, lighter toward the 

 center. In all cases the interval between the successive rhomboids is 

 but 1 or 2 half scales in width. The lateral rhomboids and triangles 

 referred to in G. adamanteus are indicated by two alternating series of 

 dark brown blotches, the first along the third and fourth lateral row, 

 opposite the apices of the rhomboids; the second along the sixth and 

 seventh, and alternating with the same; the spots occupy 1 scale, or 

 liart of 4 contiguous ones. Space between these rhomboids and the 

 yellowish lines, dull yellowish brown. Beneath nearly uniform yellow- 

 ish, slightly clouded on the sides of the scales. On the tail the 

 blotches are confluent into 3 or dark brown half rings, interrupted 

 on the surface. General distribution of lines on the head much as in 



* Original description by S. F. Baird, in Baird and Girard, N. Am. Serp., p. 5, from 

 tbe type specimens from Texas. 



