30 R. W. CROSSKEY 



segment not or only very slightly widened apically (shape elongate subrectangular) . 

 Palpi clear yellow. [g postabdomen as Text-fig. 126] . . . atra Townsend 



- Wing cell R s widely open. Scutellum with a pair of small basal setae. Third 



antennal segment very strongly widened apically (shape subtriangular axe-shaped, 

 especially in <J). Palpi pale brown to blackish brown. [European species, $ 

 postabdomen as Text-fig. 129] . . . . . . . fasciata Meigen 



10 Femora reddish yellow (at most only darkened at apices or on dorsum of fore pair). 



Cell R 5 open or just closed at wing margin . . . . . . . u 



- Femora black or blackish brown (at most only the apices reddish). Cell R b open or 



closed, often with a well developed petiole . . . . . . . 16 



1 1 Scutellum with hind margin more or less evenly rounded and with basal setae. 



Abdomen with complete and distinct sutures between Ti + 2, T3 and T4, with 

 a pair of setae on the dorsum of Ti +2 in the normal median marginal position, 

 and without laterodiscal setae on T3 and T4. Hind tibia with two ad and two 

 pd setae clearly differentiated ......... 12 



- Scutellum with strongly marked posterolateral corners and the middle part of the 



hind margin straight, without basal setae. Abdomen with the sutures between 

 Ti -f 2, T3 and T4 obliterated dorsally, with a pair of enormous setae on the 

 dorsum of Ti + 2 in the middle discal position, and with a strong laterodiscal 

 seta on each side of T3 and T4. Hind tibia with only one ad and one pd seta 

 clearly differentiated. [Specimen seen from China (Fukien)] . . Undescribed sp. 



12 Three pairs of post acr setae. Palpi yellow or orange, o* sternite 5 with lateral 



lobes in form of very long narrow downcurved processes. Abdominal T5 without 

 pollinosity, shining; pollinosity of the preceding tergites yellowish white to pale 

 golden. Basicosta yellow or yellow-orange. Upper lateral parts of the occiput 

 more or less completely haired and without strong setae just above the occipital 

 foramen . . . . . . . . . . . . .13 



- One pair of post acr setae (prescutellar). Palpi dark brown or blackish. £ sternite 



5 with lateral lobes in the form of broad straight blade-like processes. Abdominal 

 T5 almost completely and rather thickly white pollinose, not shining; pollinosity 

 of the preceding segments silvery or bluish white (no trace of yellowness). 

 Basicosta dark brown or black. Upper lateral parts of the occiput almost com- 

 pletely bare below the postocular row and with several long black setae on each 

 side immediately above the occipital foramen. [<J postabdomen as Text-fig. 124, 

 $ postabdomen as Text-fig. 133] ....... excisa Tothill 



13 Abdominal ground colour tawny red or blackish, non-metallic; T4 with extensive 



pale yellowish pollinosity similar to that on T3 or on both preceding tergites. 

 Palpi normal, evenly slender or at most very slightly enlarged at the tips, subequal 

 in length to third antennal segment. Lower calypter bare on its upper surface and 

 with short marginal fringe hair . . . . . . . . .14 



- Abdominal ground colour dark metallic purplish violet (the violaceous tinge con- 



spicuous to naked eye) ; T4 dorsum almost entirely shining non-pollinose, con- 

 trasting in appearance with extensively pale yellow pollinose preceding tergites. 

 Palpi enlarged, strongly spatulate on the apical three-fifths, longer than third 

 antennal segment [$ only known]. Lower calypter with long fine hair on about 

 the outermost quarter or fifth of the upper surface and with unusually long 

 marginal fringe hair. [$ postabdomen as Text-fig. 132] . . aenescens Malloch 



14 Abdomen tawny red with a broad blackish median vitta on Ti + 2 or on both 



Ti + 2 and T3 (appearing dark reddish brown to naked eye). Palpi uniformly 

 slender. [$ postabdomen as Text-fig. 135] . . . ocypterina Villeneuve 



Abdomen extensively blackish on dorsum and sides (ground colour appearing 



generally black to naked eye). Palpi very slightly swollen at the tips . . . 15 



15 ? postabdomen terminating in a pair of long curved tapering hook- like claspers 



(Text-fig. 131). [o" postabdomen as Text-fig. 1 28] . . b icincta Robineau-Desvoidy 



