POISONOUS SNAKES OF NORTH AMERICA. 441 



N. Amer. Fann.a, No. 5, p. Ill (1891). — Taylor, Ann. Rep. Nebraska State 



Board Agric, 1891, p. 354 (1892).— Hay, Proc. U. S. Nat. Mus., xv, 1892, p. 



387.— CouES, Hist. Exp. Lewis and Clark, i, p. 313; ii, p. 373 (1893).— 



Caiidisona confluenta Cope, in Mitchell's Res. Ven. Rattlesu,, p. 122 



(1861).— COPK, Proc. Phila. Acad., 1866, p. 309.— Allen, Proc. Boston Soc. 



N.H., XVII, 1874, p. 69, extr. p. 39.— CoUES, in Wheeler's Surv. West 100 



Mer.,V, p.604 (1875). 

 li,o2. —Crotalus lecontei, Hallowell, Proc. Phila. Acad., vi, 1852, p. 180. — Hal- 



LOWELL, in Sitgreave's Exp. Zuni and Colo. Riv., p. 139 (in part only) 



(1854). — Caiidisona lecontei, Cope, in Mitchell's Res. Ven. Rattlesu. (p. 121) 



(1861).— Hayden, Geol. Nat. Hist. Upp. Missouri, p. 177 (1862). 

 859. — Crotahis adaniaiiteus, vat. confltientns, Jan, Rev. et Mag. Zool., 1859, No. 12, 



extr. p. 28.— Jan, Elenc. Sist. Olid., p. 124 (1863). 

 1865. — Crotahis darissus, Max von Wied, Verz. Rept. Reise Noi'd. Amer., p. 65, 



pi. VII, figs. 1-3 (not of Linn.). 

 1866. — Caiidisona confluenta, var. lecontei, Cope, Proc. Phila. Acad., 1866, p. 307 (not 



of 1883). 

 1875. — Crotalus adamanteus, subsp. atrox, Yarrow, in Wheeler's Surv. West 100 



Mer., V, p. 529 (not of B. & G.). 

 1875. — Crotalus lucifer, Yarrow, in Wheeler's Surv. West 100 Mer., v, p. 529 (not 



of B. &G.). 

 1875. — 'Waudisona lucifer, var. cerberus, CoUES, in Wheeler's Surv. West 100 Mer., 



v, p. 607. 

 ' 1883. — Crotalus confliienlus, var. confluentus, Cope, Proc. Phila. Acad., 1883, p. 11. — 



Cope, Proc. Phila. Acad., 1892, p. 336.— Cope, Proc. U. S. Nat. Mus., 



XIV. 1891, p. 692(1892).— Taylor, Amer. Natural., xxvi, Sept. 1892, p. 752. 

 1883. — Crotalus confluentus, var. pulrerulenius. Cope, Proc. Phila. Acad., 1883, 



p. 11. — Crotalus confluentus pulrerulentas, Cope, Proc. U.S. Nat. Mus., xiv, 



1891, p. 692 (1892). 

 Figures. — Baird and Girard, in Marcy's Exjil. Red River, Zool., jjI. i (1854). — 

 Cooper, Pac. R. R. Rep., xii, pt. iii, pl. xii (1859). — Dumeril et Bibron, 

 Erp^t. Gener., Atlas, pl. lxxxiv bis, fig. 4 (1854). 



Description.* — Head subtriaiigular. Plates on top of head sqiiami- 

 forin, irregular, angiilated, and imbricated; scales between supercili- 

 aries (supraoculars) small, numerous, uniform. Four rows of scales 

 between the suborbital series (which only extends to the center 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 

 becoming 10 or 12 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. Rostral 

 margined with lighter. 



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 superciliaties nearly uniform in size. Line of scales 

 across from one nostril to the other consists of 6, not 4 as in G. atrox. 

 Superciliaries more prominent. Labial series much smaller. Upper 

 anterior orbitals (preoculars) much smaller, as also is the anterior nasal. 



*From S. F. Baird's description of specimens from Wichita Mts. aud Texas, in 

 Baird and Girard's N. Am. Serp., p. 8. 



