46 R. W. CROSSKEY 



8 Wing with cell i? 5 closed well before the margin and conspicuously petiolate (the 



petiole longer than r— m). Parafacials strongly haired. Three stpl setae 



GERALDIA Malloch 



- Wing with cell i? 5 open to the wing margin. Parafacials bare or haired. Two or 



three stpl setae ............ 9 



9 Parafacials either totally bare or fully haired. Arista pubescent or (in A natropomyia) 



short-plumose. Two or three stpl setae. £ palpi a t most only slightly spatulate 10 



— Parafacials strongly haired on the upper half and with two or three minute hairs 



at the ventral end adjacent to the eye, entirely bare medially. Arista long- 

 plumose. Three stpl setae. § with extraordinarily large dorsoventrally spatu- 

 late palpi (coloured bright orange and conspicuously contrasting with blackish 

 head and body). [Moderately large form, length about 10 mm, with abdomen 

 slightly shining blue-black or violaceous beneath the thin whitish pollinosity] 

 [Western Australia] ........ Undetermined gen. 



[One female specimen from Western Australia seen in BMNH] 



10 Parafacials strongly haired .......... n 



— Parafacials bare ............ 12 



11 Three stpl setae. 3 + 3 dc setae. Third antennal segment distinctly pointed on 



its outer apex. Bend of vein M further from the wing margin than from m-cu. 

 Humeral callus with several strong setae differentiated (usually 5-7). Palpi of $ 

 distinctly spatulate apically ....... ACUCERA Malloch 



- Two sternopleural setae. 3 + 4 dc setae. Third antennal segment evenly rounded 



apically. Bend of vein M nearer to the wing margin than to m—cu. Humeral 

 callus with only two strong setae clearly differentiated (only at most one or two 

 weak hair-like setae in addition). Palpi of $ evenly slender. Head profile as 

 in Text-fig. 30 PLA TYTAINIA Macquart 



12 Three sternopleural setae. Arista short-plumose. Epistome distinctly projecting 



in front of the vibrissal insertions when seen in profile, vibrissae inserted above 

 the level of the epistomal margin. First antennal segment not noticeably 

 projecting. Antennae largely bright orange . . ANA TROPOMYIA Malloch 



— Two sternopleural setae. Arista pubescent. Epistome not projecting when seen 



in profile, vibrissae inserted about level with the epistomal margin. First 

 antennal segment prominently projecting. Humeral callus with three or four 

 setae standing more or less in line. Antennae not so coloured . HOBARTIA Malloch 



13 Interfrontal area well developed, wider than a parafrontal in both sexes. Frons 



narrower in <J than 9- Arista with very long plumosity (longest hairs exceeding 

 the width of the third antennal segment). Hind tibia without pd preapical 

 seta. Wing vein i? x bare. <J without reclinate orbital setae 



TRICHOSTYLUM Macquart 

 [This genus has very much the habitus of Billaea Robineau-Desvoidy s.l. but 

 has the propleuron bare. It differs from Philotrichostylum Townsend by the 

 same character, but is otherwise exceedingly similar to this genus] 



- Interfrontal area very reduced or completely obliterated, in <j> obviously narrower 



than a parafrontal and in g eliminated by the fusion of the broad parafrontals 

 in the mid line of the frons. Frons as wide in g as in 9, much wider than an eye 

 in dorsal view. Arista with long pubescence or short plumosity (longest hairs 

 much shorter than width of antenna). Hind tibia with a pd preapical seta (in 

 addition to the normal ad and d preapicals), though this sometimes very small. 

 Wing with vein R 1 bare or setulose. g without or with one pair of reclinate 

 orbital setae (in latter case these standing very isolated near upper outer corners 

 of the wide frontal region) .... HETEROMETOPIA Macquart 



[This genus, although running out in the same couplet as Trichostylum above, 

 certainly has little or no relationship with Trichostylum and may not belong in 

 the Prosenini] 



