402 Mr. A. H. Haliday on the generic distribution 



in their favourite localities. The general colour of the body 

 is rather uniform, ranging from a dull olive or cinereous shade 

 to a shining black. The halteres are sulphureous, with the 

 base black in the dark-coloured species, brown or tawny in 

 the others. 



Sp. 1. cardamines, H. nigro-senescens, antennis subtus facie ore 

 palpis coxis et tibiis anticis totis tibiis posterioribus apice tar- 

 sisque basi fulvis ; m.f. -f — 1-^ lin. 

 Var. ft. Facie albo-micante. 

 Var. y. Antennis et mento nigris. 

 Among aquatic plants, Hollywood ; local but not rare. 

 Sp. 2. flaviceps, H. obscure viridis antennarum articulo 3° tibiis 

 tarsisque fulvis, tibuVposticis annulo fusco, ore palpisque flavis, 

 facie flava albo-micante. 

 Notiphila flaviceps. Meig. Dipt. Eur. vi. 72. — Discocerina id. 

 Macq. S. a B. ii. 527. — Hydrellia aurifacies. Desv. Myod. 791. 

 In marshes about Hollywood ; June ; rare. 

 Sp. 3. hydrocotyles,H. obscure viridis tibiis anterioribus et posti- 



carum apice palpis tarsisque fulvis, facie albissima : f. 1 lin. 

 Hydrellia communis. Desv. Myod. 791 ? 

 Hollywood ; extremely rare. 



Sp. 4. porphyrops, H. nigricans antennarum articulo 3° tibiis apice 

 tarsis basi fulvis, facie ore palpis flavis, puncto frontali albo, ocu- 

 lis hyacinthinis ; m. •§- lin. 



This distinct and beautiful species has occurred but once at 

 Hollywood among Mentha sylvestris in a ditch. The eyes are 

 large and of an exquisite purple tint, and the face remarkably 

 small. The eyes are dark green or brassy in most other 

 species. 



Sp.5. thoracica, H. thorace cinereo obsolete lineato, facie alba, 



palpis nigris, tarsis posterioribus ferrugineis; m.f. 1^ lin. 

 On the sea-coast, Hollywood ; June ; rare. 

 A very distinct species, of robust form^ and the only one 

 which has any vestige of markings on the body. The middle 

 and hind tibiae are evidently thicker than the fore pair. The 

 discoidal recurrent nerve is very near the margin. 



Sp. 6. Ranunculi, H. nigro-olivacea facie alba, tarsis posterioribus 

 basi palpisque ferrugineis, nervo transverso subobliquo : m.f. 

 1} lin. 



Abundant in meadows and marshes. This is probably the 



