34 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. 62. 
The abdomen is more or less conical and is usually much shorter 
in the male than in the female, although longer than the thorax in all 
the species. Male abdomen with seven obvious segments, the last two 
very small; dorsum of the first six in some species densely silvery 
pollinose and flattened. Male genitalia often quite large, the struc- 
ture easily made out, and of specific importance, offering more defi- 
nite specific differences than in Thereva and quite variable in general 
shape; the epiproct and hypandrium are usually shining, never 
thickly pollinose. The eighth segment of the female forms the base 
of the ovipositor and there is a terminal circlet of spines. In the 
female the abdomen is often apparently bare of pile at low magnifi- 
cations, the pile on the fifth to eighth segments very short and erect. 
Legs slender and usually red or yellow and black; sparse pile on the 
coxae in addition to the bristles; pile on the femora mostly short 
and reclinate and short on the hind femora. There are about two 
coxal bristles in front, four on the middle and hind pair; usually two 
bristles below near middle of anterior femora; an irregular antero- 
ventral row of six or seven on the hind femora; tibiae with rows of 
small bristles and several apical larger ones, the bristles of the ante- 
rior pairnot extending to the base. Wing venation typical of the 
family, cell M-3 more often closed than open, in some species petio- 
late; the wings in a few species spotted, never banded as in the 
related genus Epomyia, usually hyaline or with a mark on the outer 
side of cell first M-—2 (discal cell); in some species there is a sharp 
curve in the upper fork of the radial vein. 
SYNOPSIS OF MALES.> 
1. First antennal joint unusually thick; pile of the mesonotum nee hy- 
popygium large...... a Jo Se ae 
First antennal joint Herein Dany: dente more or ress era ie on Apis meso- 
MOGI sae oe 4, 
2. Pile of the csabigl oad we opet chine ellowiahe | iyrieples on the peau wells 
variegata Loew. 
Pilewof genitalia larcely black: orbital |bristles black: 2- = <-,4-.405---e- ee Pao 
3. Pile of mesonotum golden yellow; two scutellar bristles. 
variegata flavipilosa, new subspecies. 
Pile of mesonotum silvery white; four scutellar bristles, 
variegata occidentalis, new subspecies. 
4. Wings broad and densely spotted with brown; R-4 acutely bent near tip.. 5. 
Wings usually hyaline, never pnt R-4 not sharply bent down before the 
5. nee of frontal triangle ah a iblaer spare deut ects oo -- sc /ACHIA Adams. 
Apex of frontal triangle golden brown.. EA. ool dat . tergissa (Say). 
6. Abdomen rather flattened above, siiniee plack on the Aides) (ailvers on the dor- 
sum (haemorrhoidalis group)...... SoOWeS SES eM aha 
Abdomen more or less rounded, usually pollinese.er on tthe rides... ameeesiee ews) 
8 The eight new species in Kréber’s 1914 paper are not included in the synopses of species. Walker’s 
species are omitted, being unrecognizable from the descriptions, also occipitalis Adams, not seen by the 
writer. The female of festina Coquillett runs to couplet 28; the frons is entirely gray. 
