Syrrhophis interorbitalis: Campbell and Simmons, 1962:194, fig. 1.
Fig. 18: Left to right. Syrrhophus interorbitalis (UIMNH 38095, ×1.5), S. nivocolimae (LACM 3203, ×1.3), and S. teretistes (KU 75263, ×1.5).
Diagnosis.—Medium sized frogs, only known male 25.6 mm. snout-vent, females 20.0-26.7 mm. snout-vent length (small sample); vocal slits in males; finger tips expanded; first finger shorter than second; outer metatarsal tubercle one-third size of inner; skin of dorsum shagreened, that of venter smooth; diameter of tympanum 37.7-42.4 per cent that of eye in both sexes; pale yellow-brown ground color mottled with brown; limb bands broad, much wider than narrow light interspaces; interorbital bar very long, edged with dark brown to black ([Fig. 18]).
Remarks.—Duellman's (1958) measurements and proportions of S. interorbitalis were based exclusively on the type series, which is composed of only females; therefore his interorbitalis data are not comparable with the data for the other species in his table. Campbell and Simmons (1962) collected the only known male. The type series was collected beneath rocks in a stream bed; the collectors heard calling frogs in the bushes but were unable to obtain specimens (Langebartel and Shannon, 1956). Campbell and Simmons (1962) reported that their specimen had a poorly developed interorbital bar in life; in preservative the bar compares favorably with the bar in the female ([Fig. 18]).
Etymology.—Latin, in reference to the pale interocular band.
Distribution.—Pacific lowlands of Sinaloa, México ([Fig. 20]).
Specimens examined.—(10). MÉXICO, Sinaloa: 36 mi. N Mazatlán, UIMNH 38094-96, 67061 (holotype), 71970-74; 65 mi. N Mazatlán, LACM 13773.