The skin, lungs, and buccal cavity may all serve as respiratory surfaces in adult terrestrial amphibians. The relative role of these respiratory surfaces has been shown to be an im- portant consideration in the ecology, geographic distribution, and phylogenetic relationships of caudate amphibians (Whitford and Hutchison, 1963, 1965, 1966, 1967). Respiration in anurans has been reviewed by Foxon (1964). Information on the comparative importance of the various respiratory surfaces in anu- rans has been based primarily on the anatomical studies of vascularization of respiratory surfaces (Czopek, 1955a, 1955b; Czopek and Czopek, 1959; Bieniak and Watka, 1962). Physiological studies dealing with the role of these respiratory surfaces in anurans have been limited to the classical studies of Krogh (1904) and Dolk and Postma (1927) on the European frogs, Rana esculenta and R. temporaria, and the recent study of Vinegar and Hutchison (1965) on the green frog, R. clamitans.