In the preparation of a synopsis of the North American genera of Syrphidæ, I have found several new species that could not be placed in any of our known genera. A careful study of the figures and descriptions of exotic forms has not thrown much light upon them, and I am therefore constrained to regard them as new.

With the genera included in the present paper, and resuscitating Macquart's Toxomerus, the number now recorded from North America will reach sixty, all but five or six of which are in the writer's collection. Of these, but nine or ten have not yet been found east of the Central Plains, and the following, only, that are not now known west of that region, viz., Triglyphus, Senogaster, Pyrophaena, Doros, Ocyptamus, Rhingia, Brachyalpus, Somula, Temnostoma, Merapioidus, Pterallastis, Teuchocnemis and Lepidomyia, leaving nearly forty genera that occur entirely across the continent; indeed a large proportion of the species are identical from the Atlantic and Pacific regions.