Criteria for vertebrate subspecies, species and genera. Introduction / Charles M. Bogert. Criteria for vertebrate subspecies, species and genera. Lower categories in herpetology / Emmett Reid Dunn. Criteria for vertebrate subspecies, species and genera : mammals / E. Raymond Hall. Criteria for genera, species and subspecies in zoology and paleontology / George Gaylord Simpson. Criteria for subspecies, species and genera in ornithology / Ernst Mayr.