232 ' Orthorrhapha brachyceia. 



bristles above (in confinis with long hairs on the anterior and ventral 

 side). There are two claws, two small pulvilli, and a narrow em- 

 podium with bristles below. Wings somewhat broad; the mediastinal 

 vein terminating in the subcostal vein; this latter vein rather long, 

 reaching about to the middle, rarely short; it is somewhat distant 

 from the costa; discai vein with a larger or smaller bend on its last 

 part, but the end-part parallel with the cubital vein; posterior cross- 

 vein placed about in or after tho middle, rarely a little anterior to 

 it ; anal vein not reaching the margin, though often traceable near 

 to it. Axillary lobe well developed, but rounded. The discai bend 

 lying on a convexity. Squamulæ with the angulary lobe small, 

 bearing a long fringe, the inner part of the squamulæ with short hairs. 



The developmental stages of the genus are not known. 



The species of Argyra are very characteristic, and in the male 

 sex very beautiful flies, especially the species with silvery gloss. They 

 occur in fens and woods, generally at the horders of water at ponds, 

 streamlets and ditches, and also on other piaces where the ground 

 is humid; in sunny weather the males are then flying very quickly 

 to and fro quite low over the wet ground or muddy border, and 

 resting on it, while the females are sitting in the vicinity on leaves 

 of bushes and in low herbage: the males are also found resting on 

 leaves especially in gloomy w'eather. 



Of the genus 17 species are known from the palæarctic region; 

 9 have been found in Denmark. 



Tahle of Species. 

 Males. 



1 . Scutellum hairy above 2. 



— Scutellum not hairy above 4. 



2. Arista longer than the antennæ 3. 



— Arista shorter than the antennæ 3. magnicornis. 



3. Abdomen silvery, with yellow spots on the sides of second 



and third segments 1 . diaphana. 



— Abdomen not silvery, without yellow spots 2. Loeivii. 



4. Thorax silvery above 5. 



— Thorax not distinctly silvery above 7. 



5. Antennæ shorter than the head; epistoma black 4, leucocephala. 



— Antennæ as long as, or longer than the head; epistoma 

 silvery white 6. 



6. Arista as long as, or longer than the antennæ; front 



coxæ mainly grey 5. argyria. 



— Arista shorter than the antennæ : front coxæ mainly yellow 6. argentina. 



7. Hind metatarsus longer than the second joint; wings with 



the subcostal vein not short 8. 



