Synonymy, variation and distribution of Ptychohyla leonhard-schultzei Ahl. Studies of American frogs. IV. 1960. Aggressive behavior in dendrobatid frogs. 1966. Courtship isolating mechanisms in Costa Rican hylid frogs. 1967. Phyllomedusa buckleyi Boulenger: variation, distribution and synonymy. 1969. New species of frog in the Hyla parviceps group from Ecuador. 1969.