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198 AN ACCOUNT OF BRITISH FLIES. 
The genus Ceratopogon tabulates as follows : 
A. Antennz with the five last joints elongated. 
A, Wings with two cubital areolets, or with one, 
distant from the przebrachial. 
a Wings wholly or partly hairy, quite bare in the ¢’s 
of some species. Femora simple, unarmed. 
8 Ungues with hairy onychia; equal length in g 
and 2. 
y First tarsal joint shorter than, or of equal length 
to, second. 
6 Subcostal united to costal in middle of fore border 
or before it. I. Bipunctatus, L. 
6d Subcostal united to costal between middle of 
fore-border and tip of wing. 
2. Piceous; sides of péctus shining ; wings with 
black down ; base and a triangular costal 
tuft whitish. Piceus, Wiz. 
3. Black; thorax shiny. Gray pubescence on 
wings ; tibiz fringed with pointed lancet- 
like scales, Ciliatus, Wtz. 
yy First tarsal joint longer than second. 
6 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. (9) Brevipennis, Macq. 
6. Deep black ; thorax with black hairs, gray in 
some lights. Alacer, Wiz. 
7. Mouse-coloured, dull; thorax with tawny 
hairs, yellow and black. Murinus, Wtz. 
é6 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. 
* g. Black, not shiny; thorax clothed with long 
black hairs ; legs hairy ; tarsi white. Halteratus, Wz. 
10. Black, not shiny; thorax clothed with long 
black hairs; legs piceous ; tarsi yellow. Velox, Wz. 
11. Black, shiny; thorax clothed with short 
whitish down; legs pale piceous; long 
pale hairs. Frutetorum, Wiz. 
12. Black, shiny ; thorax clothed with gray hairs. 
Legs yellowish. Lucorum, Mg. 
13. Grayish-brown; thorax clothed with yellowish 
hairs. Scutellum fringed with few black 
hairs. Rostratus, Wiz. 
14. Blackish-brown; thorax clothed with yellowish 
hairs. Scutellum fringed with few black 
hairs. Halteres brownish ; white knobs, Brunnipes, Mg. 
15. Black; thorax shiny, yellow hairs. Legs fer- 
ruginous. Halteres yellow. Fuscus, Mg. 
16. Blackish-brown ; thorax shiny, yellow hairs. 
Legs yellowish-white. Halteres milk-white. AZinztus, Mg. 
88 Ungues with bristly hairs instead of onychia. 
Of equal length in ¢ and 92. 
y First tarsal joint longer than second. 
© Subcostal united to costal between middle of fore- 
border and tip of wing. 
17. Piceous. White down on thorax. Palpi 
brown. Legs pale yellow. Amenus, Wz. 
