In a recent sending of parasitic Hymenoptera, bred by Dr. Filippo Silvestri, at the Laboratorio di Entomologia Agraria, Portici, Italy, sent me for names, I find a new Pezomachus, represented by both sexes.

Pezomachus Silverstrii, new species.— ♀. Length, 2.6 mm.; ovipositor a little longer than the petiole of the abdomen. Black and shining, impunctate except a feeble shagreening on the pleura; the metathorax is rounded off posteriorly, and without a trace of a transverse carina; antennæ 21-jointed, the fourth joint a little shorter than the third the flagellum brown-black, the extreme apex of the pedicel, or second joint of antennæ, yellowish; legs black, with the sutures of the trochanters, the apical third of front femora, front tibiæ narrowly at base and more or less beneath, and base of first joint of tarsi, testaceous, the rest of tarsi fuscous or brownish, but a little yellowish at sutures of the joints; hind tibial spurs white.