Two new genera of Agathidiini are described and revised: Gelae Miller and Wheeler, new genus and Decuria Miller and Wheeler, new genus. Gelae differs from other agathidiines by having 11 antennomeres, a distinctly 3-segmented antennal club, no supraocular carina, no postocular temporum, 5–4–4 female tarsal formula and obsolete dorsal punctation, or, if present, inconspicuous and not serially arranged. Decuria differs from other agathidiines by having 10 antennomeres. The dramatically poor taxonomic condition of genera in the Agathidiini is discussed and problems are identified. A key to the genera of Agathidiini is presented. The following new combinations are proposed: Gelae parile (Fall), new combination, G. parvulum (LeConte), new combination, and G. cognatum (Matthews), new combination. Each are transferred from Agathidium Panzer. The following new species are described: Gelae rol, new species, G. fish, new species, G. donut, new species, G. baen, new species, G. belae, new species, and Decuria newtoni, new species. A lectotype is designated for Agathidium parile Fall.