1942] 
Neotropical Syrphidce 
89 
with across the middle, just behind and margining the suture, 
a lateral, evanescent, attenuated, medially club-shaped, opaque 
black fascia which is medially interrupted. On the anterior 
half of the mesonotum, anteriorly submarginal, there is a 
medially interrupted, wide black fascia. Pile of mesonotum 
yellow on the middle of the anterior half and in front of the 
suture, and in a narrow band in front of the scutellum in front 
of and on the post calli; elsewhere the pile is short and black. 
Pleural pile short and pale. The scutellum is opaque black on 
the basal half, brownish in the lateral corners, opaque egg-yellow 
on the remainder; its pile is short, dense and golden with a few 
longer yellow hairs on disc and rim. Abdomen: elongate, 
slender, apically pointed and shining bluish black; the first 
segment is opaque black on its posterior and lateral margins 
and corners. The second segment has a postmarginal fascia, 
medially indented, laterally attenuated, and a subbasal, medial, 
rounded, posteriorly acutely filate, opaque black spot. Viewed 
posteriorly the central portion of this segment is whitish polli- 
nose. The third segment has a similar, slightly wider posterior 
fascia and no anterior spot. The fourth segment has a post 
marginal, indented black fascia a little wider sublaterally. 
Pile of the abdomen very short, chiefly black on the black areas, 
whitish elsewhere. Legs: the femora are brownish-black, the 
apical half of first four tibiae diffusely dark brown and growing 
lighter basally and with pale yellow pile. The hind tibiae are 
quite flat, rather arcuate apically and with a very short scoop- 
like production. Its pile and pubescence is pale. Hind femora 
greatly thickened in the middle, quite narrow before apex, its 
pile chiefly brassy; its ventral apical half has many short black 
spines and some long black bristles. The short black spines 
reach to the basal third. Wings: pale grey, the stigma three 
times as long as wide, the wing almost wholly villose. 
Holotype: a female. Villarica, Paraguay, v (F. Schade). 
Microdon barbouri n. sp. 
Characterized by the general greenish color, which includes 
the face, the broad base of the abdomen, and the emarginate 
scutellum, antennae black and longer than the face. 
Female. Length 11 mm.; antennae 3 mm. additional. Head: 
almost everywhere brilliant green; golden on either side of 
the antennae and eye margins, shining black just before the 
