Leptididae. 139 



the tips of the basal cells. Veins brown. Halteres brownish witli 

 somewhat paler peduncle. 



Female. Front black in the middle, whitish grey at the sides. 

 Thorax with four whitish grey stripes, the outer placed at the margins, 

 the stripes often only to be seen on the anterior part. The basal 

 part of the wings generally more hyaline than in the male. 



Length 7,5 — 8 mm. 



A. marginata is still rarer than the preceding species, only one 

 Danish specimen exists but without particular locality. 



Geographical distribution: — Europe; its northern limit is in 

 southern Sweden. 



2. Leptis Fabr. 



Species of middle or rather large size, of somewhat slender form, 

 the colour is yellowish with more or les extended black designs. The 

 head is very short, otherwise somewhat semiglobular, narrower than, 

 or as broad as, thorax. The antennæ are inserted near to each other. 

 far below the middle. The yowls not de- 

 scending below the eyes. Antennæ three- 

 jointed, the apical joint somewhat bulb- 

 shaped, terminating in a long arista not 

 separated from the basal part of the joint. 

 The eyes are bare with the facets of equal 

 or nearly equal size. The mouth parts 

 are not different in the two sexes; the 

 proboscis is not long, the basal part of Fig. i-2. Antenna of 



labium short, the labella somewhat broad ^- '»'"'3«»'»'»- 



and much longer than the basal part of labium, somewhat protruding; 

 labrum nearly of the length of the proboscis, pointed, hypopharynx 

 a little shorter and more slender than labrum, truncate at the apex; 

 the maxillæ somewhat semitubular, pointed, as long as the labrum; 

 the maxillary paipi are indistinctly two-jointed, the basal joint very 

 small, the apical joint long, somewhat curved, pointed and densely 

 haired; it is lying along the proboscis. Thorax rectangular, somewhat 

 arched. Abdomen long, somewhat slender, nearly cylindrical, con- 

 sisting of seven not transformed segments; in the males it is trun- 

 cate at the end. the genitalia being somewhat knob-like with more or 

 less hookformed lateral laraellæ ; in the females the abdomen is some- 

 what more robust but tapering towards the apex, the last, transformed 

 segments forming an ovipositor, terminating in two small larnellæ. 

 The legs are long; the front tibiæ without, the posterior tibiæ with 



