Dolichopodidae. 223 



figure in Mon. of Dipt. of N, Am. PI. VI, fig. 29 a it would seem that outer 

 vertlcal bristles are present here). On the posterior side of tiie ocellar 

 tubercle are a pair of small hairs. The eye-facets are in the male 

 distinctly enlarged in the middle of the front side, towards the eye- 

 SLiture; sometimes {nigricans) they are enlarged in the whole upper 

 half, and thls is marked off from the lower half by a sharp dividing 

 hne. (Whether the facets are enlarged in the males with separated 

 eyes I do not know). The postocular hairs form a single row above, 

 but the whole lower half of the occiput is covered with somewhat 

 dense hairs, also present above the oral aperture. The antennæ are 

 inserted near to each other; in the females and in the males with a 

 broad frons they are placed almost in or a little above the middle, 

 but in the males with touching eyes they are placed farther down- 

 wards, below the middle ; they are short, shaped about as in Chrysotus, 

 the third joint generally broader than long and generally rounded 

 anteriorly; arista distinctly dorsal, or (in non Danish species) more 

 or less subapical. The first antennal joint has no hairs above, the 

 second has a circlet of bristles at the apex, longest above, the third 

 is densely and somewhat strongly hairy and the arista distinctly haired. 

 Epistoma of usual shape in the females and in the males with a 

 broad frons, but in the males with touching eyes it is shorter, some- 

 what impressed and directed inwards, as it forms a small angle with 

 the frons. The clypeus is short, only slightly marked off by a small 

 elevation on each side; in the female it is a little arched; generally 

 it does not reach the lower margin of eyes, though sometimes almost 

 reaching it. Proboscis slightly protruding in the male, a little more 

 in the female; it and the mouth parts somewhat stronger in the female 

 than in the male. Thorax somewhat short, almost quadratic, some- 

 what high, and arched above; pro- and metathorax small, the former 

 with small bristles above, Acrostichal bristles biserial and distinct; 

 there are five dorsocentral bristles, a humeral bristle and a couple of 

 small hairs, a posthumeral, two notopleural, three supraalar, much 

 diverging backwards, and a postalar bristle ; the propleura have some 

 (about four), not strong bristles. Scutellum bare, with two strong 

 marginal bristles, and on each side a small bristle or hair. Abdomen 

 somewhat long, sometimes shorter; it is cylindrical or slightly com- 

 pressed, for the rest constructed as in Chrysotus; the eighth segment 

 has some, generally four, strong bristles. Hypopygium as in Chrysotus, 

 and likewise almost quite hidden ; the outer lamellæ narrow, hairy, 

 sometimes larger and of varied shape. Abdomen has dot-like impres- 

 sions on the second, third and fourth segments, and less obvious on 

 the fifth. The abdominal segments have hindmarginal bristles. Legs 



