An online photographic catalog of primary types of Platygastroidea (Hymenoptera) in the National Museum of Natural History, Smithsonian Institution

New taxonomic information is given on the identities, generic classification, morphology, relationships, and geographic distribution of several hundred species of proctotrupoid wasps. The paper is based on a study of primary types of 270 species of Scelionidae, many secondary types, and other important material in 40 world museums and private collections with approximately 300,000 specimens of Proctotrupoidea having been examined. Many genera are redefined, and generic diagnoses completed or corrected. The tribal classification is reviewed; four new tribes are proposed in the subfamily Scelioninae, viz. Nixoniini, Sparasionini, Cremastobaeini, and Doddiellini.

A key to the genera of Scelionidae of the Holarctic region is given. Sixty-seven genera are recognized in three subfamilies, viz . Telenominae, Teleasinae, and Scelioninae. Seven new genera and six new species are described from America north of Mexico, viz . Aradoctonus armatus n. gen. and n. sp. (Telenominae, Telenomini), Embioctonus setiger n. gen. and n. sp. (Scelioninae, Embidobiini), Epigryon audax n. gen. and n. sp. (Scelioninae, Gryonini), Exon californicum n. gen. and n. sp. (Scelioninae, Gryonini), Harringtonia n. gen. for Baryconus cinctus Harrington (Scelioninae, Psilanteridini), Mecix texana n. gen. and n. sp. (Scelioninae, Psilanteridini), and Spiniteleia campbelli n. gen. and n. sp. (Scelioninae, Psilanteridini). The Nearctic and Palearctic faunas of Scelionidae are compared, analyzed, and tabulated on generic level. Twenty-eight plates with 207 scanning electron micrographs and line drawings are included.