CHIRONOMID.E. II5 



19. Wings bare. .......... 20 



Wings hairy. .......... 23 



20. Front metatarsi as long or longer than tibiae (2) . Chironomus. 

 Front metatarsi distinctly shorter than their tibiae. . . 21 



21. Legs, especially the front pair, sharply black and white annulate. 



Cricotopus. 

 Legs not so banded. ........ 22 



22. Posterior branch of fifth vein sinuous (15). Camptocladius. 



Posterior branch of the fifth vein straight or gently arched (6). 



Orthocladius. 



SUBGENERA OF ORTHOCLADIUS. 



a. Eyes hairy Trichocladius Kieffer. 



Eyes bare. ..... b. 



b. Pulvilli large, empodium long and filiform. 



Psectrocladius Kieffer. 

 Pulvilli wanting. ..... c. 



c. Empodium filiform. . . . Dactylocladius Kieffer. 

 Empodium not distinct. .... Orthocladius. 



23. Front metatarsi longer than their tibiae; anal angle of wings but 



slightly developed; anterior cross-vein very short and some- 

 times difficult to distinguish Tanytarsus. 



Front metatarsi shorter than their tibiae. .... 24 



24. Thorax produced conically, nipple-like, in front over the head; 



hind tibiae dilated and hairy. . . . Eurycnemus. 

 Thorax moderately produced, hind tibiae not dilated. 



Metriocnemus. 



25. Antennae with thirteen joints (counting the large basal) wings 



with anal angle; palpi three-jointed, penultimate joint swollen. 



Tersesthes. 



Antennae with fourteen joints in both sexes, the terminal joint 



only moderately elongated; male antennae plumose (Ceratopo- 



go?i, sens, lat.) ......... 26 



26. Last tarsal joint with empodium, either distinct or developed pul- 



villiform; wings usually hairy; femora without spines, tarsal 

 claws equal. ......... 27 



Last tarsal joint without empodium; wings usually bare. . 28 



27. Empodium well developed, almost as long as the claws, these with- 



out setae (12, 13, 14) Ceratopogon. 



