_External Morphology._--(Fig. 1) _Additional features not mentioned in diagnoses_: Head wider than long, about as wide as body; supratympanic fold present; canthus rostralis rounded, loreal region slightly concave, nearly vertical; nostril at tip of snout; pupil horizontal; no teeth on maxillary, premaxillary, or vomer; tongue small, round, thick, not notched behind, free posteriorly for one-sixth of length; choanae large, only partly visible from directly below; males having darkened subgular vocal sac; vocal slits present in male. Axillary membrane lacking or but slightly developed; no tubercles or ridge under forearm; two palmar tubercles; subarticular tubercles small, simple, round, flattened; tips of fingers slightly expanded, T-shaped, with prominent transverse groove; first finger shorter than second (stated as longer than second in diagnosis by Gaige, 1926:2); folds extending laterally from anus for a short distance, then downward to venter of thighs; no appendage on heel, no inner or outer tarsal folds or tubercles; inner metatarsal tubercle oval, about twice as long as wide; outer metatarsal tubercle nearly absent; no supernumerary tubercle on sole; subarticular tubercles on foot small, round, simple, and diffuse; toes T-shaped, slightly wider than digit; toes about two-thirds webbed (Fig. 1d). Skin of venter coarsely areolate; skin of flanks, throat, chest, undersurfaces of arms, tibia, tarsi, dorsal surfaces of thighs, tarsi, hands, and feet smooth; skin of dorsal surfaces of tibia, forearm, back, and top and sides of head having large horny pustules (sharply spinous in male). [Illustration: FIG. 1. _Allophryne ruthveni_, male (KU 69890); (_a_) Dorsum. (_b_) Thenar view of right hand. (_c_) Lateral profile of head. (_d_) Plantar view of right foot. x 3.5.] _Color._--Dorsum gray with irregular network of black lines and elongate blotches; flanks and labial region black with large white ocelli; dorsal surfaces of limbs gray, marked as follows: two large, elongate white spots on each thigh, concealed white spot on base of upper arm, black-edged gray transverse bars on forearms and shanks, white spot on each knee and elbow; ventral surfaces pale gray; black-edged white spot on ventral surface of thigh on each side of anal opening; chin and throat dark gray with white spots; vocal sac in male black (Fig. 1a and c). Gaige (1926) briefly described the color, which conforms to the above in all particulars. The paratype (MCZ 11790) has lost the gray color after 40 years in preservation; now (1966) the ground-color is cream-brown, and the dorsal spotting, noted by Gaige as being black, is now brown.