BY EUSTACE W. FERGUSOX AND G. F. IJILL. 461 



more yellowish in :iiiterior hall', darker posteriorly, the lateral margins with 

 similar yellowish-grey tomentum; pubescence long and fine, gi'eyish in colour, 

 ratlier scanty, denser posteriorly and above wing roots. Sides dark brown with 

 long, silky, light gxey pubescence. Scutelhtvi dark brown, with long grey 

 pubescence. Abdomen reddish, with a moderately broad, median, black vitta ex- 

 tending the length of the abdomen, and somewhat expanded on first segment; 

 lateral borders with black markings on 3-6 segments; pubescence light brown, 

 with traces ot creamy on the segmentations. Venter of a Ughter reddish-yellow 

 colour, without any black vitta; with fine greyish pubescence and a fringe of 

 shelter fine creamy pubescence along posterior margin of segments. Legs reddish- 

 yellow, tarsi with apical joints infuseate; posterior tibial spurs rather short. 

 Winffs clouded with brown, most marked along the anterior border and along the 

 cross veins; distribution of shading similar to 1). auMralis, but darker. Length, 

 11.5 mm. 



//ab.— N.S. Wales: Kendall. (Miss M. Henry.) 



Desci-ibed from two males caught on flowers in garden on 26th February and 

 18th March, 1920. Both specimens have the wings damaged at the tips, and it 

 is uncertain whether the first posterior cell is closed or open; but it is probably 

 open as in D. aitstralis. Apart from the colour of the abdomen, which is most 

 striking, the species can be separated by the structure of the 7th tergite. In D. 

 nigroviltatus the apical bol-der of this segment is practically truncate, while in D. 

 australin the margin is strongly bisinnate. the median portion being produced in a 

 strongly rounded lobe. The antenna! annulations are hard to distinguish, in this 

 respect resembling D. cmstralis, though the shape of the annulations is slightly 

 different in the two species. 



Ty|ic ill Australian Museum, Sydney. 



SiLvius IXDISTINCTUS Ric. 



Rieardo, Ann. Mag. Nat. Hist., (8), xvi., (1915), p. 262; ,S'. hilli, Taylor, 

 Proc. Linn. Soc. N.S.W., xl., Pt. 4, 1915. p. 806; S. borealis, Taylor, loc. cit., 

 p. 809. 



Specimens of S. indistinctus Ric. were detennined by Miss Rieardo, and are 

 uiifiuestionably the same as 6'. Mlli Taylor, a series of which has been examined Ijy 

 both authors, and the type by one of us (G.F.H.). Mr. Taylor was probably 

 misled in his identification of S. indistinctus (Prop. Linn. Soc. N. S. Wales, 1916, 

 xli.. Pt. 4, p. 753) by a specimen so identified by Mr. Austen and quite distinct 

 from the species as identified by Miss Rieardo herself. 



The species is a variable one in the colouration of both thorax and abdomen 

 and in the presence or absence of the median abdominal spots. 



The tyjie of S- borealis has also been examined and. though there ajipears to 

 lu' a very slight difference in that the callus is less bulbous, we cannot regard it 

 as other tlian eonspecific with S. ind^istincliis Ric. 



SiLVIUS XOTATU.S Ric. 



Rieardo. Ann. Mag. Nat. Hist., (8), xvi., 1915, p. 264; Taylor. Proc. Linn. 

 Soc. N.S. Wales, x]iv., Pt. 1, 1919. p. 43; ,S'. psarophanes. Taylor, op. cit., xlii., 

 Pt. 3. 1917. p. 520; ? S. fuliginosm, Taylor, op. cit., xl., Pt. 4. 1915. p. 810. 



This appears to be a very widespread species and to a certain extent variable. 

 Among our specimens is one from Sea Lake, !Mallee District, Victoria, which was 



