48. CROTALUS 92 
way 
212. Crotalus lucasensis Van Denburgh 
San Lucan Di1amMonp RATTLESNAKE 
Plates 98 and 100 
Caudisona atrox sonoraensis Corr, Proc. Acad. Nat. Sci. Phila., 1861, 
p- 292. 
Crotalus adamanteus atrox Cope, Bull. U. S. Nat. Mus., No. 1, 1875, 
p- 33 (part); Yarrow, Bull. U. S. Nat. Mus., No. 24, 1883, p. 75 
(part); Cope, Proc. U. S. Nat. Mus., Vol. XII, 1889, p. 147; Cope, 
Proc. U.S. Nat. Mus., Vol. XIV, 1892, p. 691 (part); Core, Report 
U. S. Nat. Mus., 1898 (1900), p. 1164 (part). 
Crotalus atrox Van Densuracu, Proc. Cal. Acad. Sci., Ser. 2, Vol. 5, 
1895, p. 156; Netson, Mem. Nat. Acad. Sci., Vol. XVI, 1921, 
pp. 114, 115; Terron, Mem. y Rev. Soc. Cient. Antonio Alzate, 
Vol. 39, 1921, pp. 165, 168, 190 (part). 
? Crotalus confluentus Mocquarp, Nouv. Arch. Mus. Hist. Nat., Paris, 
Ser. 4, Vol. I, 1899, p. 332. 
? Crotalus confluentus var. atrox Mocquarpb, Miss. Sci. au Mexique, 
Pt. III, Rept., 1909, p. 969, pl. 77, figs. 5, 5a (part). 
Crotalus lucasensis Van Denburcu, Proc. Cal. Acad. Sci., Ser. 4, Vol. 
X, No. 2, 1920, p. 29, pl. 3, fig. 1 (type locality, Agua Caliente, 
Cape Region of Lower California, Mexico); Van Denpurcu 
& Srevin, Proc. Cal. Acad. Sci., Ser. 4, Vol. XI, 1921, pp. 52, 70; 
Nexson, Mem. Nat. Acad. Sci., Vol. XVI, 1921, pp. 114, 115. 
Description—tLarge. Head broad, flat-topped, varying 
in outline according to position of fangs. Rostral usually 
higher than wide, in contact with anterior nasal. Two nasals, 
Usually two preoculars and two to four internasals. A large 
scale just in front of supraocular. Supraocular large but 
not raised into a horn-like process; separated from its fellow 
by from six to eight irregular rows of scales. About 14 to 
18 superior and 15 to 19 inferior labials; first pair of latter, 
if not divided, meeting on median line in front of a single 
pair of genials. About five rows of scales between supra- 
labials and eye. Scales in about 27 rows, keeled except in 
one or two rows on each side. Gastrosteges varying from 186 
to 199. Urosteges 17 to 26. 
