26 Psyche [March-June 
transverse suture and at junction of third and fourth ab- 
dominal segments. 
One male. West border Matto Grosso, Brazil, May, 1931 
(R. C. Shannon) . Type in the U. S. National Museum. 
Stenomicrodon n. subgen. 
Head in profile not especially long, the occiput above not 
more than normally developed, the front quite flat, of mod- 
erate width. Ocelli in a small, nearly equilateral triangle. 
Antennae situated near the top bf head, elongate, first joint 
at least as long as remaining joints. Cheeks inconspicuous 
and eyes bare. Abdomen elongate, several times as long as 
wide. The first segment flattened and excavated on each 
side. A deep constriction at the junction of the third and 
fourth segments and in the female slightly between the 
fourth and fifth segments. Scutellum without spines. 
Femora slightly thickened, with more than usually strongly 
developed patches of bristly setae on the base of the third 
femora in both sexes as well as on the others. This extensive 
setiferous patch is quite differentiated from the surrounding 
pile. Third vein sends an adventitious vein down into the 
first posterior cell. Corners of first and second posterior 
cells broadly rounded, without spines apically. Wings in the 
known species are dark purplish brown. 
Subgenotype : Stenomicrodon purpureus n. sp. 
Stenomicrodon purpureus n. sp. 
Differing from Microdon stenogaster Curran in the thicker 
third antennal joint, silvery pile, deeper scars on the hind 
femora and lighter colored pile. 
One female, Tainan, Formosa (Rolle). Type in the au- 
thor’s collection. 
Oligeriops n. gen. 
Head very broad from above; vertex enormously de- 
veloped. * Ocelli situated on the summit in an equilateral tri- 
angle. Front in consequence quite broad, deeply punctate, 
eyes reduced in size, bare ; cheeks bulging, together with the 
wide, slightly diverging face, densely long pilose. Head in 
profile more or less smoothly and evenly round. Antennae 
set about the middle. First and third joints elongate, the 
