152 Orthorrhapha brachycera. 



as in Dolichopus; it is strong, and has, as in this genus, a longer, more 

 slightly chitinised median tooth, curved downwards at the end, and a 

 shorter, more strongly chitinised lateral tooth at each side; the median 

 tooth is furcated or two-pointed at the end, and labrum strongly 

 semitubular, so that the lateral teeth lie considerably below the median. 

 Hypopharynx strong, elongated triangular, curved a little down at 

 the apex; it is of the length of labrum. The maxillary palpi are 

 ovate, squamiform, with bristles at the end. The basal part of labium 

 and the labella are of approximately the same length, the latter are 

 broad, roundish and with bristles at the margin. Thorax rectangular, 

 somewhat hlgh and a little arched above; pro- and metathorax small, 

 the former with a transverse row of small bristles above ; no chitin- 

 ised metasternum. The acrostichal bristles biserial and distinct; 

 there are six long dorsocentral bristles, longest behind; further two 

 humeral bristles of the same, or about the same size, two post- 

 humeral, the inner weak, two notopleural, a præsutural far forwards, 

 three supraalar and one postalar bristle. The front part of the disc 

 has small hairs. The propleura have hairs and a prothoracic bristle. 

 Scutellum is bare, it has four bristles, the lateral small. Abdomen 

 somewhat compressed, slightly narrowed towards the end; it is other- 

 wise in both sexes constructed about as in DoUchopus; in the male 

 the second sternite is less or not emarginated in front; the fourth 

 and fifth sternites are incised posteriorly, but distinctly present. The 

 hypopygium is exposed, somewhat pedunculated, laid up under the 

 venter; it is principally constructed as in DoUchopus; sometimes the 

 posterior ventral lobes are strongly projecting and pedunculated (and 

 hence they have been considered as a pair of inner lamellæ, and the 

 hypopygium has been described as possessing more lamellæ than 

 commonly). The outer lamellæ are smaller or larger, hairy at the 

 margin, but not split into teeth. In the female the ovipositor ends 

 with spines above and a single plate below. The abdominal segments 

 have hindmarginal bristles. The second, third and fourth segments 

 have distinct dot-like impressions at the side margin. Legs somewhat 

 long, coxæ a little elongated; in the male the front tarsi are generally 

 more or less dilated and haired; the hind metatarsus a little shorter 

 than the second joint. The legs have short hairs, the coxæ, especially 

 the front coxæ, have more or less bristly hairs at the apex; the 

 middle coxæ have a strong bristle in the middle on the front side 

 near the outer edge; the hind coxæ have a bristle in the middle on 

 the outer side; there are more or fewer preapical bristles on the 

 posterior femora, and rows of bristles on the tibiæ; the latter have 

 also apical or preapical bristles, smallest on the front tibiæ. Hind 



