Length 7-1/2 lines. Black; the orbits of the eyes, the face before the antennae, the mandibles and palpi yellowish-white; the flagellum with the joints from the 14th to 25th white. Thorax: a line on each side before the tegulae, a spot beneath the wings, two at the sides of the pectus, the anterior coxae in front, and a narrow line on each side of the scutellum yellowish-white; the anterior and intermediate legs and a spot beneath the posterior tibiae rufo-testaceous; the wings hyaline, the nervures black. Abdomen: a minute spot at the lateral apical margins of the three basal segments, and a large central one on the two apical segments, white. _Hab._ Key Island. Gen. CRYPTUS, _Fabr._ 1. CRYPTUS SCUTELLATUS. _C._ ferrugineus; tibiis posticis tarsisque albo annulatis; scutello tuberculato. _Female._ Length 5 lines. Ferruginous; the face testaceous-yellow, an elongate black spot on the vertex enclosing the ocelli and extending to the insertion of the antennae; the latter black, with the scape ferruginous in front. Thorax: the scutellum elevated, forming a compressed tubercle, its side view wedge-shaped; the wings hyaline the nervures black, the base of the wings yellowish; the apical joints of the intermediate tarsi, the tips of the posterior femora, the extreme base of the tibiae, their apical half, and the tarsi black; the intermediate portion of the tibiae yellow; the apical segment of the abdomen black. _Hab._ Aru. Gen. MESOSTENUS, _Grav._ 1. MESOSTENUS PICTUS. _M._ niger; capite thoraceque flavo striatis et punctatis; pedibus flavis nigro et ferrugineo lavatis; segmentis abdominalibus flavo marginatis; alis hyalinis. _Female._ Length 8 lines. Black; a large ovate spot on the cheeks touching the mandibles, the labrum, palpi, inner orbits of the eyes, and from the 7th to the 10th joints of the antennae yellowish-white. Thorax: an ovate spot in the middle of the disk of the mesothorax, the tegulae, a spot beneath them, two larger spots beneath the wings, the scutellum, a spot on the postscutellum uniting with another at the base of the metathorax, a trilobed spot at its apex, and a subovate one on each side yellowish-white; the coxae white with black stains on the intermediate and posterior pairs; the femora white beneath, the anterior and intermediate pairs with a black line above, the posterior pair ferruginous above; the tibiae and tarsi whitish beneath, stained more or less fusco-ferruginous above; wings hyaline. Abdomen: all the segments with yellowish-white fasciae on their apical margins, the fasciae continued beneath; the ovipositor about the length of the abdomen, the valves broadest at their apex. _Hab._ Aru. 2. MESOSTENUS AGILIS. _M._ niger; antennis medio albis; thorace pedibusque albo variegatis; abdominis marginibus fasciis albis.