OCR Text |
Show 158 ME. E. E. AUSTEN ON NEW DIPTEEOUS INSECTS. [Jan. 17, BACCHA PEEVIDA, sp. n. (Plate V. fig. 11, d •) d. Length 10 mm. General colour orange; abdomen deep dull orange, with metaUu-brown posterior borders to the segments, fiat, not contracted basally, but expanding regularly to the end of the fourth segment: wings suffused with brown, slightly paler towards the tips; alulce of full size. Face and cheeks pale yellow, thinly clothed with pale yellow pile ; the face receding, with a very small tubercle. Front orange pollinose, with a brown median stripe from the angle of the eyes to the upper margin of the very slight antenniferous projection; the latter pale orange in front, shining, with a black dot above the antenna?; the front clothed with brown pile. Antennas orange, short, third joint rounded at the tip, with the upper margin brown ; arista brown, yellowish at the base ; vertical triangle bronze, black at the apex, long, narrow ; ocelli remote from the vertex. Dorsum of thorax metallic orange, somewhat iridescent, not pollinose, with three narrow faint brown stripes (one median and one on either side of it), which do not reach more than halfway: pleurae metallic yellow ; scutellum dull saffron-yellow. Abdomen: first segment brownish orange ; second segment with a metallic transverse band on the anterior as well as the posterior fourth ; this segment is somewhat shining, especially in the median line ; on the third segment the metallic brow-n transverse band on the posterior fourth expands somewhat towards the sides, and there is a semi-obsolete faint brown median stripe, extending from the anterior margin to the posterior border ; on the fourth segment the posterior band is only about half the width of that on the third, but it expands into a median triangle, which is connected by a faint brown stripe w ith the anterior margin, and also into a quadrate area on each side, which occupies rather more than half the length of the segment; the median stripe is somewhat clavate at its anterior extremity, and this is also the case with the similar stripe on the third segment; the fifth segment is wholly shining, and the brown portion is about equal to the orange in area: the posterior border is, however, much narrower, while the median stripe is broader and more sharply defined than on the previous segments, and that which corresponds to the brown lateral quadrate areas on the fourth segment is here represented by an ovate mark on each side, extending nearly to the anterior margin and situated nearer the middle line, so that the lateral margin of the segment as far as the posterior border is orange; the orange portion of the fifth segment on each side of the median stripe is therefore deeply indented by a brown notch ; genitalia brown at the tip : with the exception of a tuft of pale yellow hairs on each side of the first segment, the pile on the abdomen is black, appressed, and very short and sparse, though it is somewhat longer on the fifth segment. Legs yellow ; posterior pair deeper orange, but without bands. Third longitudinal vein |