_Male._ Length 9 lines. Ferruginous; the head of a yellow testaceous, with the vertex and antennae black; the scape ferruginous in front; the mandibles black. Thorax: the mesothorax and scutellum transversely rugose, the former with two deeply impressed lines in front, which converge inwards, and meet in the middle of the disk; wings hyaline, with a yellow tinge on the anterior pair, the nervures black; a black stripe crosses the middle of the marginal cell, and terminates at the inferior margin of the discoidal cell; the legs ferruginous, with the posterior tarsi black. Abdomen smooth, shining, ferruginous. _Hab._ Aru. 2. RHYSSA VESTIGATOR. _R._ ferruginea; antennis, mesothorace, metathoracisque basi nigris; abdomine lineari, nitido et laevi; alis hyalinis, apice subfuscato. _Male._ Length 9 lines. Head testaceous-yellow, with the vertex ferruginous; the antennae fusco-ferruginous. Thorax black, with the prothorax, a large oblique spot beneath the wings, the scutellum, and metathorax yellow, the base of the latter black; the mesothorax and scutellum rugose; the metathorax smooth and shining; the legs ferruginous, with the anterior coxae in front and the posterior pair behind yellow; the posterior coxae black beneath; wings hyaline, faintly clouded at their apical margins. Abdomen elongate, linear, glossy, smooth, and shining, ferruginous, with the base and lateral margins blackish. _Hab._ Aru. Gen. BRACON, _Fabr._ 1. BRACON BASALIS. _B._ capite, thorace, pedibus anticis et intermediis, femoribus posticis ferrugineis; tibiis tarsisque et abdomine nigris, segmento basali flavo; alis fusco-hyalinis. _Female._ Length 4-1/4 lines. The head, scape in front, thorax, anterior and intermediate legs, the posterior coxae, trochanters, and femora, and the first segment of the abdomen, and a semicircular spot in the middle of the base of the second, yellow-ferruginous; the antennae, the posterior tibiae and tarsi, fuscous; abdomen shining black; the thorax smooth and shining; the wings fusco-hyaline. The basal segment of the abdomen with a longitudinal impressed line on each side, the second segment with an oblique depression, the third with an impressed line, curved forwards and extending to the lateral margins; the base of the segment has a row of short, deeply impressed striae; the ovipositor shorter than the abdomen. _Hab._ Aru. 2. BRACON ALBO-MARGINATUS. _B._ capite, thorace pedibusque ferrugineis; abdomine nigris annulis albo-marginatis; alis fusco-hyalinis. _Female._ Length 4-1/2 lines. Head, thorax, and legs ferruginous, smooth, and shining; antennae and abdomen black, the latter smooth and shining, the posterior margins of the third and following segments with a narrow bluish-white fascia; the posterior tarsi slightly fuscous; the wings fusco-hyaline; the ovipositor a little longer than the abdomen. _Hab._ Aru.