20 Orthorrhapha brachycera. 



TaUe of Genera. 



1. Hind coxæ witli only one bristle on the outside ; antennæ 



short in both sexes ; colour not silvery • 2. 



— Hind coxæ with more than one bristle on the outside; 

 antennæ in the male more or less elongated; colour in 



the male generally more or less silvery 3. 



2. Arista subapical ; frons broad; epistoma generally very 

 narrow in the male, and narrower than the frons in the 



female; pulvilli not enlarged 10. Chrysotus. 



— Arista distinctly dorsal; eyes of the male touching on 

 the frons, in the female the frons not broader than the 

 epistoma; the pulvilli of the front tarsi enlarged in the 



male 1 1 • Diaphoriis. 



3. Basal joint of antennæ hairy above; middle tibiæ with 



more than tvi'o bristles below 12. Argyra. 



— Basal joint of antennæ bare above; middle tibiæ with 



one or two bristles below 13. Leucostola. 



III. Rhaphiinae. 



Arista apical, rarely somewhat subapical; the second antennal 

 joint simple, not overlapping the third, or {Syntormon) inserted thumb- 

 like into it; the third joint is elongated and long to very long in the 

 male, short, triangular or ovate in the female ; rarely it is of the same 

 length in both sexes. Postocular bristles forming a single row, or the 

 lower part of occiput more or less densely covered with hairs. 

 Acrostichal bristles biserial, in most species of Syntortnon uniserial, 

 but generally a little biserial behind. Prothorax with more or less 

 numerous hairs on the pleura, of which one or some may be bristly. 

 Hind coxæ without, or with one to two or three bristles on the out- 

 side. Hypopygium more or less imbedded or {Systenus) quite free 

 and pedunculated; the outer lamellæ sometimes long, more or less 

 thread-like or forked ; at other times small. — This subfamily is very 

 natural ; the genera included in it form the genus Rhaphium of Loew 

 in 1850 (Stett. Ent. Zeitg. XI, 1850, 85), and Meigen has them as 

 Porphyrops in Vol. VII (together with Achalcus) here uniting his 

 Rhaphium (Vol. IV) with Porphyrops after the exclusion of Argyra 

 from this latter. In Neue Beitr. V, 1857 Loew forms or limits the 

 now accepted genera, after Haliday in 1831 had estabhshed the 

 genus Machaerium. — Aldrich, as said, piaces Argyra and Leucostola 

 in this subfamily. 



Tahle of Genera. 



1. Second antennal joint simple 2. 



— Second antennal joint inserted thumb-like into the third 15. Syntormon. 



2. Third joint of antennæ long in both sexes, broad at 



