-March, 1905. | gg 



4. O. chalyhcBUS Wied. : when I first caught this, at Ormesby Broad 



in June, 1S80, I at once concluded that it was new to 

 Britain, because of its brilliant steel-blue colour. It was 

 not at all uncommon there, and I have since taken it at 

 Lymington, Hants. The blackish hind tibise distinguish it 

 in both sexes. 



5. G. assimilis Staeg. : not uncommon near Upware (but not in 



Wicken Fen) in July, 1875. J have also taken it at Chip- 

 penham Fen, in the Norfolk Broads, and at Rannoch, 



6. O. aerosus Fall. : the commonest small species over all Britain, 



and easily known by the black face of the male. The femora 

 are always rather darkened above, but a common variety {Q. 

 Dahlbomi Zett.) has the femora, especially the front pair, 

 considerably more obscured. The var. is most common in 

 Scotland, and, as Zetterstedt observed, seems to be a little 

 larger than typical G. cerosuts. 



12. LAMPROCHROMUS Mik 



This genus may be allied to Gi/mnopternus, where its acrostical 

 bristles would place it ; or, as is more commonly considered the case, 

 to Sympycnus. 



L. elegans Meig. : very uncommon at present, though possibly from 

 its being overlooked. I have taken single males at Lynd- 

 hurst, Landport near Lewes, Wicken, and I think one female 

 at Wisbech. 



13. CHRYSOTUS Meig. 

 These very small bright green flies are abundant, but in many 

 cases are very difficult to name with certainty, Wherever a species 

 occurs it is usually in abundance, and consequently series of good 

 specimens should be taken in promising spots. Our twelve species 

 comprise all except five or six of those known to occur in Europe, and 

 two or three more may occur in Britain. A small species, very near 

 C. gramineus, has occurred in Norfolk amber. 



1 (4) Femora mainly yellow. 



2 (3) Femora all yellow ; front coxte with black hairs ; comparatively largo 



species 1. neglectus Wied. 



3 (2) Hind femora black at tip ; front coxoe with yellow hairs ; small species... 



2. cilipes Meig. 



4 (1) Femora mainly black. 



5 (8) Hind trochanters and base of femora yellow. 



6 (7) Small species; hind tibise moderately ciliated 3. pulchellus Kow. 



