198 



AN ACCOUNT OF BRITISH FLIES. 



The genus Ceratopogon tabulates as follows : 

 A, Antennae with the five last joints elongated. 

 A. Wings with two cubital areolets, or with one, 

 distant from the prcxbrachial. 



a Wings wholly or partly hairy, c|uite bare in the $ "s 



of some species. Femora simple, unarmed. 

 ji3 Ungues with hairy onychia ; equal length in $ 



and ?. 

 y First tarsal joint shorter than, or of equal length 



to, second. 

 c Subcostal united to costal in middle of fore border 



or before it. i. Bipiinctatus, L. 



^5 Subcostal united to costal between middle of 



fore-border and tip of wing. 



2. Piceous ; sides of pectus shining ; wings with 



black down ; base and a triangular costal 



tuft whitish. PiceitSy Wiz. 



3. Black ; thorax shiny. Gray pubescence on 



wings ; tibise fringed with pointed lancet- 

 like scales. Cilia/ us, Wtz. 



yy First tarsal joint longer than second. 



i Subcostal united to costal in middle of fore-border 

 or before it. 



4. Black ; thorax with short yellow and long 



black hairs, Crassipes, Wiz. 



5. Black, shiny ; thorax with black hairs. ( ? ) Brevipannis, Macq. 



6. Deep black ; thorax with black hairs, gray in 



some lights, Alacer, Wtz. 



7. Mouse-coloured, dull ; thorax with tawny 



hairs, yellow and black. Muriims, Wtz, 



tit) Subcostal united to costal between middle of 

 fore-border and tip of wing. 



8. Black, shiny ; thorax clothed with long 



yellowish-white hairs. Titillans, Wtz. 



9. Black, not shiny ; thorax clothed with long 



black hairs ; legs hairy ; tarsi white. Halteratits, Wtz, 



10. Black, not shiny ; thorax clothed with long 



black hairs ; legs piceous ; tarsi yellow. Velo.x, Wtz. 



11. Black, shiny; thorax clothed with short 



whitish down ; legs pale piceous ; long 



pale hairs. Fnitdorttm, Wtz. 



12. Black, shiny ; thorax clothed with gray hairs. 



Legs yellowish, Litcorui/i, Mg. 



13. Grayish-brown ; thorax clothed with yellowish 



hairs. Scutellum fringed with few black 



hairs. Kostratiis, Wtz. 



14. Blackish-brown; thorax clothed with yellowish 



hairs, Scutellum fringed with few black 



hairs. Halteres brownish ; white knobs, Bruniiipcs, Mg. 



15. Black ; thorax shiny, yellow hairs. Legs fer- 



ruginous. Halteres yellow. Fiisctis, Mg, 



16. Elackish-brown ; thorax shiny, yellow hairs. 



Legs yellowish-white. Halteres milk-white. Miniitus, Mg. 

 /3/3 Ungues with bristly hairs instead of onychia. 



Of equal length in $ and '^ . 

 y First tarsal joint longer than second. 

 J Subcostal united to costal between middle of fore- 

 border and tip of wing. 



17. Piceous, White down on thorax. Palpi 



brown. Legs pale yellow. Amauiis, Wtz. 



