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

218 UNIVERSITY OF KANSAS PUBLS., MUS. NAT. HIST,
Specimens examined.—5 km. SE Palmito, Durango (in Sinaloa), 1880 m.
(' KU 79232); 19.2 km. NE Santa Lucia, 1940 m. (• KU 78973).
Literature record.—7 and 9 mi. {byroad) NE El Batel (Zweifel, 1954:149).
Crotalus molossus molossus Baird and Girard
Crotalus molossus Baird and Girard, Catalogue of North American reptiles,
p. 10, 1853 (type locality, Fort Webster, Santa Rita del Cobre, New
Mexico).
Crotalus molossus molossus: Gloyd, Occ. Pap. Mus. Zool. Univ. Michigan,
325:2, January 28,1936.
Remarks.—Klauber (1952:87) reported that specimens of Crotalus
basiliscus and C. molossus from southern Sonora show intergradation
in several characters, and that no actual overlap in the ranges
of the two species had been demonstrated.
A female, collected near El Fuerte, has 181 ventrals, 20 subcaudals,
25-25-22 dorsal scale rows, 17-16 supralabials, 16-16 infralabials,
32 dorsal body blotches, and six tail rings. The dorsal
blotches are open laterally (see Klauber, 1936:259, fig. 78), and the
tail is nearly solid black. The tail length is 5.3 per cent of the total
length. Our specimen shares certain characters with C, basiliscus,
but because of the low number of ventrals and subcaudals, the distinctive
dorsal pattern, the nearly solid black tail, and a knowledge
of C. basiliscus from the same general area we assign the specimen
to C. molossus.
Specimens of C. basiliscus have been taken within about 50 kilometers
southwest (near sea-level) and about 50 kilometers northeast
(about 520 meters elevation) of the locality of this specimen of
molossus {elevation about 150 meters). It is probable that the two
species are sympatric in northern Sinaloa. We leave the final clarification
of the relationships between C. basiliscus and C. molossus
to future workers.
Distribution in Sinaloa.—Known only from the northern foothills.
See Fig. 89.
Specimen examined.—6 km. NE El Fuerte, 150 m. ( 8 KU 78964).
Crotalus stejnegeri Dunn
Crotalus stejnegeri Dunn, Proc. Biol. Soc. Washington, 32:214, 1919 (type
locality, Plomosas, Sinaloa),
Remarks.—One male of this rare species has 175 ventrals, 42 subcaudals,
28-27-22 dorsal scale rows, 14-14 supralabials, 14-16 infralabials,
2-2 preoculars, 4-3 postoculars, 3-3 suboculars, 38 dorsal body
blotches, about 12 tail bands (indistinct on posterior part of tail);
the tail length is 13.9 per cent of body length. The color pattern