The Bees of the World - Charles Duncan Michener - Google Books

https://books.google.de/books?id=bu_1gmY13FIC

A comprehensive, worldwide treatment of all groups of bees - 1200 genera and subgenera, including more than 16,000 species. In extensive introductory sections, Charles D. Michener examines the evolution of bees from wasps, the relations of the families of…