1921.] 99 



Villeiieuvia. — The shape of the head and especially the face easily 

 distinguishes this subgenus. The head is markedly dichoptic in the 

 male, with a wide frontalia. Frontal row of bristles in the female with 

 the upper one or two pairs not reclinate or retro-divaricate as is usually 

 the case. Arista short, very little hmger than third antennal joint. 

 Sexual dichroism — as usual throughout tliis division — very marked, the 

 females being lighter in colour than the males. Four pairs of post- 

 sutural dorso-central bristles ; two to thi-ee ]:)airs of strongly-developed 

 laterally approximated presutural acrostichal bristles, and numerous other 

 minute bristles between the rows of dorso-centrals. Chaetotax}^ of legs 

 as in Spilogona, but bristles not so strongly developed. Cubital and 

 discal veins diverging towards tip of wing. 



Gymnodia. — Distinguished by the shape of the head, especially by 

 the narrow facial orl)its about the middle being flattened in the same 

 plane as the face, and consequently practically invisible in prolile. Eyes 

 large and deep, closely approximated on frons in male and occupying 

 almost the whole of the head in profile. Frontal bristles absent on the 

 whole of the narrowest part of frons (about half its length). Jowls 

 narrow. Frontal prominence rounded, and only narrowly visilile in 

 profile in the male. Sexual dichroism considerable. Acrostichal bristles 

 iri-egularly quadriserial, the outer rows composed of stronger, more 

 regular, bristles, and no tiny hairs between these rows and the dorso- 

 centrals. Four pairs of post-sutural dorso-central bristles. Legs slender 

 and sparingly bristled, much as in Division II (one bristle behind middle 

 tibiae, one antero-ventral and one antero-dorsal bristle on hind tibiae), 

 only one preapical bristle to all tibiae. Cubital and discal veins con- 

 verging towards tip of wing, often (in non-British species) with the 

 discal vein markedly upcurved towards the tip. 



Neolimnopliora. — Eyes small, widely separated on frons in both 

 sexes. Frontal orbits very wide in both sexes ; frontalia linear or even 

 completely hidden ; inter-frontalia in the female veiy broad and long, 

 reaching to front of frons. Facial orbits and jowls exceptionally wide. 

 Face .very short and concave. Antennae and arista both very short. 

 Sexual dichroism very slight. Prosternal plate between front coxae with 

 a row of short bristly hairs on each side. Chaetotaxy of legs as in 

 Gymnodia and Division II. Cubital and discal veins somewhat con- 

 verging towards tip of wing. 



The three subgenera included under Division II are more difficult 

 to differentiate from each other (especially in the females) than are 

 those under Division I, and have many characters in common, in addition 



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