The Amphibians and Reptiles of Sinaloa, Mexico - Smithsonian ...

AMPHIBIANS AND REPTILES OF SINALOA, MEXICO 213
of heavy forest and in regions cleared for agriculture. One was
found alive near San Ignacio about 60 meters from a stream. Although
uncommon, this snake is known and feared throughout the
coastal lowlands.
Distribution in Sinaloa.—Coastal lowlands south of Culiacan.
Specimens from Sonora (Bogert and Oliver, 1945:393) suggest the
species inhabits the foothills of northern Sinaloa. See Fig. 89.
Specimens examined.—49 mi. S Culiacan (LACM 7193); 7.5 mi, N Mazadan
(LACM 7192); 1 mi. S Rancho Huanacasde (LACM 7191); Rosario, 150 m.
(*KU 73644); San Ignacio, 210 m. ( • KU 73643).
Literature records.—Escuinapa; Mazadan (Gloyd, personal communication);
Mazatlan (Bogert and Oliver, 1945:393); Presidio (Bomenger, 1896:522).
Additional record.—Escuinapa (AMNH 4002-05).
Crotalus atrox Baird and Girard
Crotattts atrox Baird and Girard, Cat. North Amer. Rept., part I, p. 5, 1853
(type locality, Indianola, Calhoun county, Texas).
Remarks.—According to Klauber (1952:102) there were no valid
records of C. atrox from Sinaloa, Dixon, Sabbath, and Worthington
(1962:98) reported the sympatric occurrence of atrox and C. basiliscus
in Sinaloa.
Two males and two females have the following characters:
ventrals, 168, 172, 173, 178; subcaudals, 25, 26, 20, 19; dorsal scale
rows, 25-25-23, 27-25-22, 23-24-23, 27-25-22; supralabials, 15-14,
?-15, 15-14, 14-14 (excluding left side of KU 67738); infralabials,
18-17, ?-16, 16-16, 16-15 (excluding left side of KU 67738); preocu-
Iars or postoculars, 2-2 in each specimen; suboculars, 3-4, 4-4, 2-3,
4-4; width of black tail rings (in scales), 3.5, 3.0, 3.0, 2.0; and width
of white tail rings (in scales), 3.5, 4.0, 3.0, 3.0.
Distribution in Sinaloa. Known only from the northern lowlands.
See Fig. 89.
Specimens examined.—El Carrizo, 12 m. ("KU 83418); 5 km. NW El
Carrizo, 12 m. (*KU 83417); 48 km. N Los Mochis, 15 m. (" KU 67738);
Santa Maria Island, 3 m. (*KU 69938).
Additional records.—15.5 mi. N Fuerte, Rio (SU 24092); 33,2 mi. N Los
Mochis (FAS 14678).
Crotalus basiliscus basiliscus (Cope)
Caudisona basilisca Cope, Proc. Acad. Nat. Sci. Philadelphia, 16:166 (type
locality, Colima).
Crotalus basiliscus basiliscus: Gloyd, Nat. Hist. Misc., 17:1, April 23, 1948.
Remarks.—Nine males, seven females, and four specimens of
unknown sex have the following characters, respectively: ventrals,
179-188 (183.9), 182-198 (189.3), 187, 187, 184, 185; subcaudals,
14—3685