POISONOUS SNAKES OF NORTH AMERICA. 441 



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



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



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



Caudisona conjluenta Cope, in Mitchell's Res. Yen. Rattlesn., p. 122 



(1861).— Cope, Proc. Phila. Acad., 1866, p. 309.— Allex, Proc. Boston Soc. 



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



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

 1852.— Cro*rt/«.s leconfei, Hallowell, Proc. Phila. Acad., vi, 1852, p. 180. — Hal- 



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



(1854). — Caudisona leconfei. Cope, in Mitchell's Res. Yen. Rattlesn. (p. 121) 



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

 859. — CrotaJns adamaiiteus, var. confluentns, Jax, Rev. etMag. Zool., 1859, No. 12, 



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

 1865. — Crolahis durisan-s, Max vox Wied, Yerz. Rept. Reise Nord. Amer., p. 65, 



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

 1866. — Caudi)iona conjluenta, var. leconfei, Cope, Proc. Phila. Acad., 1866, p. 307 (not 



of 1883). 

 1875. — CrotaJus adamanteus, subsj). atrox. Yarrow, in Wheeler's Surv. West 100 



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

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



of B. &G.). 

 1875. — 'iCaudisona lucifer, var. cerherus, Coues, in Wheeler's Surv. West 100 Mer., 



V, p. 607. 

 1883. — Crofahts conftacntus, var. cnnftuentus, 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 confiucntus, var. pnlrerulenfus, Cope, Proc. Phila. Acad., 1883, 



p. 11. — Crotalus confluentus j)nlcerulentus, Cope, Proc. U.S. Nat. Mus., xiv, 



1891, p. 692 (1892). 

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

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

 Erp^t. Gener., Atlas, pi. Lxxxiv bis, flg. 4 (18.54). 



Description.* — Head siibtriangular. Plates on top of liead squami- 

 foriii, irregular, aiigulated, and iiubricated ; scales between snpercili- 

 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. Eostral 

 margined with lighter. 



This species bears a considerable resemblance to C. atrox, but the 

 body is more slender and compact. Scales on tlie top of the head 

 anterior to the superciliaries nearly uniform in size. Line of scales 

 across from one nostril to the other consists of 0, not 4 as in C. 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. and Texas, in 

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



