32 



Oithonhapha brachycera. 



are equally Ihickened to the point, and dirocted backwards, there are, 

 especially in the niiddle on each segment four such bristles, and then 

 a pair on each side, and again more laterally some sliort 

 bristles of the same nature; besides there are some more, 

 , „ similar but short bristles, and finally there are some long 

 bristles of common form, especially a pair on each seg- 

 ment on the lateral margin. Each segment has a trans- 

 verse row on the ventral surface of some curious pencil- 

 > ' vv W - * tl shaped bristles, intermingled with common bristles. There 

 is a pair of prothoracic spiracles, and, as far as I could 

 detect, six small abdominal spiracles, the last two seg- 

 -. ments being without such spiracles. In the apex there is 



År a transverse split surrounded by a coronet of feathery 



hairs. The larvæ live in mud ; they hibernate and the 



Fig.U. O.tri- transformation to pupa and the development of the imago 

 lineata, cast .11 



.' . take i)lace m sprme or summer, 

 pupa skin x ,t, ., • ni n 



a little more ^ "^ Oxycera species are generally not common ; they 



than 4. occur in the vicinity of water, at lakes and in the low 



herbage at the horders of brooks. 



Of the genus 40 species are known from the palæarctic region, 



7 species are hitherto found in Denmark. 



Tahle of Species. 



1 . The ground colour green or yellowish green with black 



designs 1 . trilineata. 



— The ground colour black with yellow designs 2. 



2. Abdomen black, only with a yellow spot at the base and 



one at the apex, or one at the apex alone 3. 



— Abdomen with yellow spots also on the middle segments 4. 



3. Abdomen black with a yellow spot at the base and one 



at the apex 4. leonina. 



— Abdomen with a yellow spot only al Ihe apex 5. terminata. 



4. The yellow spots on the abdomen reaching near to the 

 middle ; species larger, not below G,5 mm 5. 



— The yellow spots on the abdomen confined to the sides, 

 widely separaled in the middle: species smaller, not above 



4,3 mm 6. 



5. The yellow stripes on the thoracic disc connected with 



the yellow humoral spot 2. Meigenii. 



— The yellow stripes on the thoracic disc not connected with 



the humeral spot 3. FaUenii. 



6. Scutellum quite yellow, legs all yellow; frontal triangle 

 in the male black, vertex in tlie female black. and the 



tliorax with two yellow stripes on the disc 6. formosa. 



— Scutellum and leg.« more or less black or blackish; frontal 

 triangle in the male silver white, vertex in the female 



yellow and the thoracic disc black 7. jn/gniæa. 



