| OCR Text |
Show 146 MR. E. E. AUSTEN ON NEW DIPTEEOUS INSECTS. [Jail. 17, first segment steely, with a tuft of black hairs projecting from the anterior angles, behind which is a tuft of yellow hairs ; second segment steely on the anterior third above, on the sides for more than halfway, and on the hind margin, the remainder of the segment dull black, with a yellow dot on each side ; third segment steely on the lateral margins, and with a narrow transverse steely band in front and behind, elsewhere dull black, with four oval yellow dots arranged in the form of a quadrilateral, the anterior pair twice as far apart as the posterior; fourth and fifth segments •steely on the lateral and posterior margins, elsewhere dull black, and each with four oval yellow dots arranged as on the third segment ; genitalia small, concealed: the abdomen is broadly spatulate, expanding from the base of the third segment to the posterior margin of the fourth, and contracting thence to the tip ; the second segment is stout and cylindrical, with a fringe of hairs on each side, yellow in front and black behind ; the remainder of the abdomen is sparsely clothed with short appressed black pile. Legs black, with short, close-fitting black pile ; the tarsi flattened. Wings suffused with brown, with a darker area at the base, which is paler towards the posterior margin, and extends a little beyond the anterior cross-vein on the costal side : alulce well-developed. Ega, Brazil (Bates) : one specimen. This species is allied to Baccha aclspersa, Fab., but is at once distinguished by the infuscation of the entire wing. The terminal section of the fourth vein is also much more oblique in this species than in B. aclspersa. BACCHA LEVISSIMA, sp. n. (Plate IV. fig. 15, d •) d • Length 10| to 11^ mm.; length of wing 6| to 7 mm. Metallic bronze-black, with dead-black markings on the abdomen ; the latter greatly attenuated: wings very short, infuscated; alulas rudimentary. Face and cheeks metallic steely black, clothed (except on the tubercle) with cinereous pollen; facial tubercle prominent. Front With a pentagonal dead-black patch in the angle of the eyes, on each side of which, when viewed from behind, is a shimmering white dot : front elsewliere and antenniferous process metallic black, the latter with a flattened rugose area above. Vertical triangle black ; the short pile on the front and vertical triangle black. Antennae small; the first two joints black, the third brown, oval; arista blackish brown. Occiput black, with silvery pollen, and fringed with short whitish hairs. Thorax rather dull, metallic bronze-black ou the dorsum, shining metallic greenish black on the pleura?; a narrow dead-black median stripe on the anterior part of the dorsum, not extending beyond the region of the transverse suture : on either side of this stripe the dorsum in front is brownish pollinose, when viewed from behind or from the side. Scutellum metallic black; scutellum and dorsum finely punctate, almost bare. Abdomen: first segment metallic steely; second segment steely, with a broad dead-black transverse band, |
