Asilidae. 25 



shining, the hairy stripes fully developed, broad aud distinct, greyisli 

 white; the hairs at the hind margin of the mesopleura and the long 

 hairs on the metapleura whitish. Scutelkim rugose with yellow pubo- 

 scence. Abdomen black, sparingly clothed with short, yellow pube- 

 scence, at the lateral margin of the first segment longer hairs. Venter 

 black, generally with somewhat pale incisures and slightly longer pube- 

 scence. Genitalia with longish, yellowish hairs. Legs yellow, the coxæ 

 black, whitish pruinose on the outer side and with long, white hairs 

 which are nearly wanting on the hind coxæ ; anterior tibiæ blackish brown 

 at the apex, and the tarsi, with exception of the base of the metatarsus, 

 likewise blackish brown; anterior femora sometimes with a blackish 

 patch above at the apex ; the hind femora may be quite ferrugineous, but 

 generally they are black above in the middle and the black colour may 

 be extended nearly along the whole upper side and going downwards 

 so that it reaches round the femora to a greater or lesser extent; 

 hind tibiæ black with a larger or smaller basal part yellow; the hind 

 tarsi quite black. The hind tibiæ are very distinctly thickened at the 

 apex, and the hind metatarsi are somewhat thickened though only 

 slightly broader than the following joint. The pubescence on the legs 

 yellowish, the fringe on the hind femora whitish, that on the tibiæ 

 pale brownish ; the scattered long, thin hairs white ; the stronger bristles 

 which in this species are long and rather weak are brownish yellow, 

 they are wanting on the anterior femora. Wings slightly yellowish, 

 a little more at the base towards the anterior margin; the veins 

 blackish brown. Halteres yellow. 



Female. Quite agreeing with the male, only the abdomen is a 

 little broader. 



Length 9 — 12,5 mm. ; the species is smaller than rufipes, but large 

 females may exceed small males of rufipes in size. 



The pupa has a length of 11 — 12 mm. 



Remarks. This species is nearly related to i'ufipes, but it may 

 easily be distinguished by the small antennal tubercle and the colour 

 of the hind legs. The species has hitherto gone under the name of 

 flavipes Meig. Meigen says (Syst. Beschr. VI, 330) that his D. gracilis 

 is identical with D. hyalipennis in the collection of Fabricius. This 

 may be so, but as already Low has stated (1. c. 428) , this does 

 not make gracilis Meig. identical with hyalipennis F., since Fabricius 

 described his hyalipennis after Danish specimens in the collection 

 of Lund. Low continues: „Fabricius beschrieb seine Dioctr. hyali- 

 pennis nach dånischen, in Lund'schen Museum vielleicht noch auf- 

 zufmdenden Exemplaren; sie konnen nicht wohl einer andern Art als 

 der in Danemark nicht seltenen Dioctr. flavipes angehort haben; 



