Dolichopodidae. 169 



— Gubital and discai veins not or slightly con- 

 verging, first posterior cell thus not or only 

 slightly narrowed towards the end; scutellum 



distinctly short-haired ; postocular bristles black 2. Subg. Gymnopternus. 



1. Subg. Hercostomus. 



Gubital and discai veins more or less converging (in nigripennis 

 only slightly). Antennal arista almost bare, only microscopically hairy 

 or nearly so, in chrysozygos and nanus a little more haired. Scutellum 

 almost bare, only with a few hairs above and some at the margin; 

 it has two strong marginal bristles and at each side a small hair; 

 this latter is large in Sahlbergi and somewhat large in chrysozygos^ 

 in nigripennis it is very small. Front tibiæ with one or two ventral 

 or postero-ventral bristles, only nanus has none; hind metatarsus as 

 long or almost as long as the second joint, or somewhat shorter, only 

 in nanus it is much shorter. The male hypopygium somewhat high 

 and compressed, but not in vivax and nanus; on the ventral side it 

 has a pair of lobes in the middle, which are more or less broad and 

 directed downwards, only in viva.t narrow and directed backwards; 

 in nanus there is only a pair of posterior ventral lobes; the lateral 

 pair of the inner lamellæ are generally somewhat lancet-shaped, the 

 median pair often somewhat claw-shaped. ^ The outer lamellæ are 

 larger or smaller, generally of a somewhat triangular shape ; in nanus 

 they are narrow and somewhat long. — It will be seen, that nanus 

 in several respects differs from the other species, and it points some- 

 what towards Hypophyllus, its hypopygium is also pointed at the end 

 on each side in a similar way as in this genus. 



Tahle of Species. 



1 . Lower postocular bristles pale 2. 



— Lower postocular bristles black 6. 



2. Femora yellow 3. 



— Femora black 5. 



' I am not sure that the appendages which I have in this subgenus termed 

 median inner lameUæ are in all cases in reahty such, and answering to the 

 same in Dolicliopus. It is possible that they might answer to the posterior 

 ventral lobes, as they seem in some cases (e. g. chrysozygos) to be a direct con- 

 tinuation of the edge of the hypopygium ; then the other ventral lobes might 

 answer to the middle lobes in Dolichopus, and there would be no median 

 inner lamellæ. But against this view seem to speak the facts in vivax, where 

 there seem to be two pairs of ventral lobes, and besides inner median lamellæ, 

 and in nanus, where there are posterior ventral lobes and also inner median 

 lamellæ. 



