313 



Family Sepsidae 



Meroplius stercorarius. 



Small, shining black or reddish flies. 



Head more or less spherical, the occiput usually quite convex, face 

 carinate; one or two pairs of vertical bristles, one or no orbitals, post- 

 vertical bristles divergent; antennas decumbent, the third segment oval, 

 the arista usually l^are; i)arafacials very narrow, reduced to an orljital 

 line; palpi vestigial. Mesonotum usually aeiculate or pollinose and not 

 pubescent, its setula? usually in three longitudinal rows; scutellar bristles 

 usually two, rarely four in numljer; either One or two pairs of dorsocen- 

 tral bristles; sternopleura usually in part or entirely pruinose. Auxili- 

 ary vein curving so as to terminate obviously before the end of the first 

 longitudinal vein, costa not broken, the third and fourth veins more or 

 less converging; anal vein straight and abbreviated. Legs of the male 

 usually deformed and armed with spines or thorn-like projections, usual- 

 ly located on the front pair. Abdomen with l)ut sparse pubescence or 

 fine setulffi, often constricted at the second segment and bearing a few 

 bristles; male genitalia usually prominent, symmetrical, eomi)rising a 

 hypopygium with paired lateral valves, each tipped by a prong or flat 



