jg Orthorrhapha hrachycera. 



— Acrostichal bristles uniserial (sometimes a little ir- 

 regularly biserial behind), or wanting; only biserial 

 in AchalciiH, Thrypticus and Medeterus (see above) ; 

 the second antennal joint never thumb-like inserted 



into the third IV. HydropJwrinae. 



2. Arista dorsal, or when subapical the third joint short 



and rounded 3. 



— Arista apical or practically so; the third antennal 

 joint long in both sexes^ or generally long only in 

 the male, shorter and more or less oval in the 

 female: hypopygium generally more or less imbedded, 

 the outer lamellæ often more or less thread-like, 

 sometimes forked; in Systenus the hypopygium pe- 



dunculated III. Bhaphiinae. 



3. Postocular bristles forming a single row also below, 

 or when the lower part of occiput has dense hairs 

 the discai vein is forked ; arista dorsal ; only one 

 prothoracic bristle, or none, and only one bristle on 

 the hind coxæ ; when it is otherwise the discai vein 

 is either forked, or the colour not metallic ; hypopygium 



free, pedunculated (only hidden in Eutarsus) I. DoUchopodinae. 



— The lower part of occiput covered with dense hairs, 

 when not distinctly (Chrysotus) the third antennal 

 joint short and the arista subapical; more than one 

 prothoracic bristle, or when this not distinct, the 

 hind coxæ with more than one bristle; colour me- 

 tallic, at most abdomen with yellow spots ; hypo- 

 pygium small, not pedunculated, more or less hidden II. Diaiihorinae. 



I. Dolichopodinae. 



The antennæ havo the arista dorsal; the second joint somewhat 

 overlapping the third, except in Sciapus and Neurigoiia (or in the 

 latter to a very slight degree). The postocular bristles form a single 

 row, only Sciapus has the lower part of occiput covered with dense 

 hairs. Acrostichal bristles biserial. Generally one prothoracic bristle^ 

 and one bristle on the outside of the hind coxæ, but Sciapus and 

 Neurigona may have more. Hypopygium of the male exposed and 

 pedunculated, only hidden in Eutarsus. — The subfamily is scarcely 

 quite natural; Aldrich forms a group for Sciapus together with related 

 American genera, and one for Neurigona, and he piaces Eutarsus in 

 Diaphorinae, and this way of dividing the group is perhaps correct. 



Table of Genera. 



1. Discai vein forked 1. Sciapus. 



— Discai vein not forked 9 



