OCR Text |
Show 138 ME. E. E. AUSTEN ON NEW DIPTEROUS INSECTS. [Jail. 17, so that the outer extremity of the first posterior cell is wide : alulas rudimentary. Mysol Is., Malay Archipelago ( Wallace) ; one specimen. The type of this species was described by Walker (Journ. Linn. Soc. vii. p. 212) as being possibly the male of his species Baccha purpuricola, the type of which is a female. The yellow face and variegated abdomen of the present species, however, render its identity with B. purpuricola absolutely impossible. This species is clearly allied to Baccha moluccana, Doleschall (Natuurk. Tijdschr. Ned. Ind. xiv. p. 412, tab. iii. fig. 2), from Amboina, the abdomen of which, as figured by Doleschall, is strikingly similar to that of the present species; the face of Doleschall's species is, however, black in the middle and yellow on the sides, and he expressly states that the scutellum is black. BACCHA REEULGENS, sp. n. (Plate IV. fig. 4, § .) 2 • Length 13 m m . Front, face, and cheeks metallic dark purple, thinly clothed with pale pile ; facial tubercle not sharply defined. Antennas orange-yellow ; third joint oval. Thorax and scutellum metallic purplish violet, nearly bare ; postalar callosities brownish. The abdomen spatulate from the commencement of the third segment, thinly clothed with short blackish pile; the first two segments metallic blackish, the remainder brilliant metallic pansy-purple. Legs yellow; posterior femora with a faint indication of a narrow brownish ring beyond the middle; distal third of posterior tibiae and posterior tarsi brown. Wings hyaline, with the costal border to the tip of the third vein (including the costal, subcostal, and marginal cells) and a central area, which includes the basal cells, rather less than the basal half of the submarginal cell, rather less than the basal third of the first posterior cell and the basal two-thirds of the discal cell, and faintly extends to the posterior margin at the tip of the anal cell, brown : alulas of full size. Bouru Is., Malay Archipelago ( Wallace) : one specimen. This species is allied to Baccha purpuricola, Walker (Journ. Linn. Soc. iii. [iv.] p. 129), from Key Is., but is distinguished at once by the colour of its thorax. BACCHA TRIANGULIPERA, sp. n. (Plate IV. fig. 5, d •) S 2 • Length 13 m m . ( $ Y2\ mm.). Front, face, and cheeks yellow, with short pale yellow pile; a narrow dark brown median stripe extending a little more than halfway clown the face from the antennae. Vertical triangle in d shining black, very long and narrow, extending more than one-third of the distance between the occiput and antennae. Front of 2 with a brownish triangular spot immediately above the antennae; very narrow above, metallic black, with parallel sides for one half its length from the occiput. Occiput dull black, pollinose, with a fringe of glistening whitish hairs. Antennas orange, third joint |