26 Orthorrhapha brachycera. 



S. platypterus with a small Arachnid as prey, and I liave observed 

 S. Wiedemanni attacking a small fly. 



Of the genus about 36 species are known from the palæarctic 

 region; 5 have been found in Denmark, 



Tahle of Species. 



1. Hind metatarsi much longer than the second joint; in 

 the male either the fourth joint of the front tarsi com- 

 pressed and dilated, but not lobed, or the middle tarsi 



with the third and fourth joint compressed and white .... 2. 



— Hind metalarsus as long as or slightly longer than the 

 second joint; in the male either the fourth joint of the 



front tarsi lobed, or all tarsi simple 3. 



2. Epistoma rather narrow in both sexes; posterior cross- 

 vein straight; wings in the male broad, and middle tarsi 



with the third and fourth joint compressed and white. . 1. platypterus. 



— Epistoma broad in both sexes; posterior cross-vein very 

 or somewhat curved outwards; wings in the male not 

 broad, and front tarsi with the fourth joint compressed 



and dilated 2. nervosiis. 



3. Posterior cross-vein considerably longer than the last part 

 of the postical vein ; posterior coxæ yellow, or only slightly 



greyish ; fourth joint of front tarsi lobed in the male . . 3. Wiedemanni. 



— Posterior cross-vein shorter, or at most as long as the 

 last part of the postical vein; posterior coxæ, or at all 

 events middle coxæ, distinctly grey; tarsi in the male 

 simple 4. 



4. Abdomen without bands ; frons greenish 4. longulus. 



— Abdomen with conspicuous bands ; frons grey ........ 5. contristans. 



1. S. platypterus Fabr. 



1805. Fabr. Syst. Antl. 270, 20 (DoUchopus). — 1824. Meig. Syst. 

 Beschr. IV, 36, 2, Tab. XXXIV, Fig. 14 {Psilopus). — 1862. Schin. F. A. 

 I, 182 {Psilopus). — 1903. Kat. palåarkt. Dipt. II, 291. — Leptopus tiptu- 

 larius Fall. 1823. Dipt. Suec. Dol. 23, 1. — Psilopus tipularius Zett. 1843. 

 Dipt. Scand. II, 623, 1, et 1849. VIII, 3105, 1, et 1855. XII, 4643, 1, et 

 1859. XIII, 5071, 1. 



Male. Head higher than broad; vertex and frons grey, bristles 

 black. Epistoma narrow, greyish white. Palpi whitish, a little yel- 

 lowish. Occiput grey; the postocular hairs white, downwards some- 

 what long, and the whole lower part of occiput covered with hairs; 

 above the postocular hairs are a little yellowish, and the uppermost 

 are a little stronger, and one or more may be black. Antennæ yel- 

 low or ferruginous, the third joint and the arista brown or blackish 

 brown. Thorax metallic green, greyish pruinose and hence dull; the 



