The spots on the feet, tarsi, knees, thighs, flanks and upper arm are white in preservative, but in life possibly were red or yellow. These colors usually fade to white in preservative. Red or yellow spots are common aposematic colors in frogs. _Variation._--Eight measurements were taken on each specimen and four ratios were computed; these are summarized in Table 1. Gaige's illustration of the holotype shows that it has a greatly reduced pattern, whereas the paratype and three of the other five known specimens have relatively large and numerous spots. The male (KU 69890) and one female (AMNH 70108) have a reduced pattern intermediate between that of the holotype and the four other specimens. TABLE I.--Variation in Measurements and Proportions of Allophryne ruthveni. (Ranges in parentheses below means.) --------------------------+----------+----------------- Character | Male (1) | Females (5) --------------------------+----------+----------------- Snout-vent (in mm.) | 20.6 | 23.6 | | (18.4-31.0)[A] | | Tibia/snout-vent | 0.43 | 0.43 | | (0.41-0.47) | | Tympanum/head width | 0.12 | 0.15 | | (0.14-0.16) | | Eyelid/interorbital space | 0.55 | 0.53 | | (0.49-0.56) | | Tympanum/eye length | 0.40 | 0.46 | | (0.42-0.50) --------------------------+----------+----------------- [Footnote A: Holotype is reported to be 31 mm. snout-vent length (Gaige, 1926). The largest measured by us was 26.2 mm. snout-vent.] The dorsal spinules are most pronounced and extensive on the male (Fig. 1) and less so in all other specimens examined. The illustration of the holotype suggests that it has equally prominent, but fewer, spinules (Gaige, 1926). The holotype, a gravid female, is the largest known specimen (31 mm., snout-vent length). Another gravid female (AMNH 70108) has a snout-vent length of 26.2 mm. _Distribution._--All known specimens have been found in the foothills of the northeastern face of the Guiana Massif in British Guiana. FAMILY POSITION The following characters of _Allophryne_ are those generally held to be useful in determining family relationships: 1. Presacral vertebrae procoelus, eight in number. 2. Parahyoid absent. 3. Free ribs lacking. 4. Bidder's organ absent. 5. Intercalary cartilages present in digits; phalangeal formulae 3-3-4-4 and 3-3-4-5-4. 6. Coccyx articulating with sacrum by two condyles. 7. Tarsal bones not fused.