NoHTii Amekicak DirTiiRA. 55 



Antenna; small, sliort, three-jointed, the third joint oval or reniform, 

 with a dorsal arista. Face small, narrow. Proboscis small. Hypo- 

 pyjfium thickeneil, clubbed; ovipositor usually elonjrate and folded 

 under tlie abdomen. Basal cells of wing well developed, the tiiird 

 elongate; one submarginal, three posterior cells present ; first pos- 

 terior cell narrowed in the margin Piitnculcs 



Tiie flies are met with on flowers or in sweepings, and are readily 

 distinguished by their large spherical head. Larvie parasitic ; pupa; 

 obtected. 



PLATYPEZIDuE. 



Head hemispherical or spherical, as broad or broader than the 

 thorax. Face usually broad and short. Antenna porrect, three- 

 jointed, the third somewhat elongate, circular, pear-shaped or coni- 

 cal, with a terminal arista. Proboscis short, but little prominent. 

 Eyes bare, contiguous in the male; ocelli present. Abdomen com- 

 paratively short ; genitalia projecting in C a 1 1 o m y i a. Legs short 

 and strong ; hind legs often thickened, especially the tarsi ; pulvilli 

 present. Basal cells of wing small, the anal usually reaching to tlie 

 margin ; third longitudinal vein simple, the fourth sometimes fur- 

 cate ; discal cell sometimes wanting. Small flies. 



1. Discal cell present. 2 



Discal cell wanting 3 



2. Fourth longitudinal vein simple Callomvia 



Fourth vein furcate Platypeza 



3. Fourth vein simple Platycnema 



Fourth vein furcate ° ( )i'ktia Meig. 



Callomyia Meigen, Ivlassif. 1804. 

 Platypeza Meigen, Illiger's Mag. 1803. 

 Platycnesia Zetterstedt, Dipt. Scand. I, 1842. 



CESTKID^:. 



Moderately large to large, plump, thickly or thinly pilose flies. 

 Head large ; face and front broad. Antennae small, three-jointed, 

 more or less concealed in a subantennal cavity or grooves; first two 



