Member Zoological Society London. Member British Ornith. Union; member American Society Naturalists, Society Study Evolution (vice president 1956-1957), Society Vertebrae Paleontology, American Society Zoological, American Society Mammalogy, American Society Ichthyologists and Herpetologists, Cooper Ornithology Society (president 1948-1951), Phi Beta Kappa, Sigma Xi.
.; Member Committee on Classification and Nomenclature North America Birds, 1940-1957, chairman since 1960. Member International Commision on Zoological Nomenclature, president since 1963.