Etymology.—Latin, in reference to the pale ground color in comparison with that of S. modestus.
Distribution.—Low elevations in coastal Nayarit and on Islas Tres Marias ([Fig. 20]).
Specimens examined.—(12) MÉXICO, Nayarit: 18.8 mi. NW Ahuacatlán, UIMNH 7808; San Blas, UMMZ 115452 (holotype), 115453-57; 17 km. NE San Blas, 150 m., MSU 5085; 12.8 km. E San Blas, UIMNH 71979; 31 km. E San Blas, UIMNH 71978; 13.5 km. N Tepic, UIMNH 71980-81.
Syrrhophus teretistes Duellman
Syrrhophus teretistes Duellman, 1958:2-3, 10-14, pl. 2, fig. 2 [Holotype.—UMMZ 115451, from 4.8 km. NW Tepic, Nayarit, México, 840 m.; collected on August 12, 1956, by William E. Duellman]. Gorham, 1966:167.
Diagnosis.—Medium-sized frogs, males 19.2-23.2 mm. snout-vent length, single known female 24.8 mm. snout-vent; vocal slits in males; finger tips widely expanded; first finger shorter than second; inner metatarsal tubercle about three times size of outer; skin of dorsum shagreened, that of venter smooth; tympanum partially concealed, its diameter 28.6-43.8 per cent of eye in males; ground color brown vermiculated with dark brown to nearly black; upper arm and thigh banded; interorbital light bar absent.
Remarks.—S. teretistes appears to be most closely related to S. pallidus; I consider it to be an upland derivative of pallidus. Morphologically, the differences between the two are few, but lacking evidence of genetic exchange they are retained as species.
Etymology.—Greek, in reference to the whistle-like nature of the call.
Distribution.—Moderate elevations (840-1200 meters) in the Sierra Occidental of Nayarit, Sinaloa, and Durango, México ([Fig. 20]).