170 



Orthorrhapha brachycera. 



3. Squamulæ with a yellow fringe 1 . gracilis. 



— Squamulæ with a black fringe 4. 



4. Antennæ black 2. germanus. 



— Antennæ mainly yellow 3. chrysozygos. 



5. Large species ; proboscis not elongated ; wings somewhat 

 brownish; middle metatarsus in the male with bristles 



below 4. Sahlbergi. 



— Small species ; proboscis rather long ; wings strongly brown 



or blackish ; middle metatarsus in the male simple .... 5. nigripennis. 



6. Legs black 6. vivax. 



— Legs yellow 7. nanns. 



Fig. 50. Hypopygium of H. brevicornis, ven- 

 tral lobe, lateral and median inner lamellæ 

 and outer lamellæ are seen. 



2. Subg. Gymnoptemus. 



Gubital and discai veins not or slightly converging. The antennal 

 arista somewhat distinctly haired (in angustifrons, assimilis and aerosus 

 rather short-haired). Scutellum distinctly hairy above, in chalyheus 

 only slightly; it has two strong marginal bristles, but only in chalyheus 



there is besides a small hair at 

 each side, the other species 

 have none. The front tibiæ 

 have no ven tral bristles, only 

 in chalyheus there is a posterior 

 bristle. Hind metatarsus much 

 shorter than the second joint, 

 in chalyheus only slightly shorter. 

 The hypopygium of the male 

 is alike in all species (Fig, 50); 

 it is more or less long, on 

 the ventral side there is about in the middle, or at all events long 

 before the apex, a pair of lobes of characteristic shape; they are 

 long and slender, directed backwards with the end curved upwards, 

 and with some hairs; of the inner lamellæ the lateral are short, flat 

 and of a characteristic shape, the ventral apical corner pointed and 

 the dorsal corner going out into a spine; the space between the 

 edges is thin and transparent; the median inner lamellæ are more 

 styliform, but a little dilated; the sheath of penis reaches to the end 

 of the hypopygium; in chalyheus the ventral lobes issue more back- 

 wards and are shorter, and the inner lamellæ are longer. The outer 

 lamellæ are small, somewhat roundish, the marginal hairs not long; 

 in chalyheus they are larger, with longer hairs. 



Table of Species. 



1. Femora mainly black 2. 



— Femora yellow 3. 



