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Show 1893.] ME. E. E. AUSTEN ON N E W DIPTEROUS INSECTS. 145 yellow, pectus and metanotum metallic black. Scutellum brownish yellow. Abdomen: the anterior margin and sides of the first segment pale yellow ; on the second segment a narrow transverse band, slightly notched in the median line behind and situated just beyond the middle of the segment; third segment with a cres-centic band in the middle, narrowly interrupted in the median line, concave posteriorly, and nearly three times as broad as the band ou the second segment; the sagittate markings are situate on the anterior half of the fourth segment, and directed anteriorly, they are narrowly separated in the median line and are truncated in front by the hind margin of the preceding segment; on the fifth segment the yellow markings consist of deeply notched bases of arrow-heads, situated one on each side of the anterior half of the segment, the whole of the remainder of the arrow-heads being, as it were, hidden beneath the fourth segment; the inner angles of the bases of the arrow-beads are longer than the outer, aud the notches are very much larger than in the case of the arrow-heads on the previous segment; sixth segment wholly purplish black : the markings on the fourth and fifth segments are of a deeper yellow than the others. Legs yellow; the posterior femora and tibiae each with two brown bands, the band near the base of the femur being more diffuse and less distinct than the others; similar bands are faintly indicated on the middle legs. Wings with a brownish tinge, which becomes concentrated at the tips ; distal half of subcostal cell brown ; third longitudinal vein straight; distal portion of fourth vein, closing first posterior cell, short, upright. Cinchona, Jamaica; June ( W. Fawcelt, Esq.) : one specimen. This species of Baccha is distinguished from any other known to me, by the shape of the conspicuous yellow markings of the abdomen. BACCHA SIGNIEEEA, sp. n. (Plate IV. fig. 8, d •) d • Length 11^ m m . Face and cheeks metallic blue-black, with black pile; face narrowly shimmering white on the sides above ; facial tubercle sharply defined, conical; front (including the large antenni* ferous projectiou) metallic black, with a dull black quadrate median area behind. The first two joints of the antennas black ; the third brown ; the arista brown. Thorax dull velvety black on the dorsum, with three stripes on each side of the median line metallic black; the innermost stripe on each side is very narrow and tapering, and does not reach much more than halfway ; the intermediate stripe is broader, and also tapers, but fuses posteriorly with the lateral stripe, which is very broad indeed, and extends to the scutellum; the two outside stripes are divided by the transverse suture; the lateral stripe includes the post-alar callosity; pleurce metallic bronze-black. Scutellum metallic black; thorax and scutellum clothed with short black pile. Abdomen dull velvety black, with yellow dots and metallic bands; PEOC. ZOOL. SOC-1893, No. X. 10 |