Dolichopodidae. 343 



2. Scutellum with only two bristles 1 . bisetus. 



— Scutellum with four bristles 3. 



3. Epistoma bright metallic above 2. halticus. 



— Epistoma quite whitish 4. 



4. Jowls present; front tibiæ with an apical tooth on the 



ventral side 3. praecox. 



— Jowls practically absent; front tibiæ without toolh at the 



apex 4. Utoretis. 



5. Wings with two spots 6. 



— Wings with numerous spots 7. nebulosus. 



6. Epistoma metallic above 5. hipunctatus. 



— Epistoma almost quite whitish in the male, brown in the 



female 6. horealis. 



1. H. bisetus Loew. 



1857. Loew, Neue Beitr. V, 24. — 1903. Kat. palåarkt. Dipt. II, 342. 

 — Hydrophorus inaequalipes 1851. Walk. (nec Macq.) Ins. Brit. I, 186,10. 



Male. Head about as high as broad; frons and vertex brownish 

 grey. Epistoma broad, very slightly narrowed above, greyish white. 

 Palpi grey. Occiput greenish, greyish brown pruinose above, whitish 

 grey below; postociilar bristles black, the hairs below whitish. No 

 distinct jowls. Antennæ black, third joint almost not longer than 

 broad, pointed ; arista about as long at the antennæ. Thorax brownish 

 olive, dull, sometimes a little greenish, especially at the sides; in the 

 middle two darker, narrow and approximated stripes; the dorso- 

 central bristles somewhat strong, numerous. Scutellum with two 

 bristles. Pleura slightly greenish or æneous, grey pruinose; propleura 

 with about three black prothoracic bristles. Abdomen green, some- 

 what greyish pruinose, especially at the sides ; it is clothed with short, 

 pale hairs, slightly longer at the sides, and especially at the hind 

 margins towards the apex. Venter greyish. Hypopygium quite hidden, 

 only the short, brown or dark brown outer lamellæ sometimes seen 

 below. Legs green, coxæ grey pruinose and also femora and tibiæ 

 somewhat pruinose; tarsi blackish. The legs have short, chiefly black 

 hairs, and also a fine, pale pubescence, especially distinct towards 

 the end of the tibiæ and on the tarsi, and the front tibiæ are silvery 

 pubescent on the anterior side; coxæ pale-haired, front coxæ with 

 some black bristles ; front femora with two rows of spines below, not 

 reaching to the apex; front tibiæ a little curved, and thickened to- 

 wards the end, with a row of short spines below; posterior femora 

 and tibiæ with various scattered and not long bristles. Wings some- 

 what long and narrow, a little brownish; veins brownish black, paler 

 at the base; the last part of the discai vein very slightly curved, a 



