Hymenopterenfauna von Paragnay. 215 
truncate at the apex, the hypopygium produced beyond the apex 
of the dorsal segment, narrow and rounded at the apex, without 
spines or lobes. The first ventral segment is broadly but shallowly 
divided from the second. 
Black; the spines of the tibiae testaceous. Wings flavo-hyaline, 
clouded in the radial cell; stigma ferruginous; nervures ferruginous 
at the base, fuscous at the apex. 
Length 16—18 mm. 
Hab. Tucuman, N. Argentina, 14 specimens; Rio Branco, 
Amazonas, one specimen. 
The mandibles are similar to those of true Elaphroptera, which 
it also resembles in the emargination of the elypeus and the long 
hairs on the head and thorax; but the hypopygium approaches 
much more nearly to the lateralis group. The shape of the anterior 
margin of the elypeus in South American species of Thynnidae varies 
much in nearly allied species and can only be used with great 
caution as a generic character. The locality Rio Branco may be 
erroneous. 
Elaphroptera strandi n. sp. 
(Bi. Kie..'S.) 
3. Mandibles strongly elbowed and flattened, bidentate. Ulypeus 
deeply emarginate at the apex, the emargination in the shape of an 
elongate horseshoe extending to the middle of the elypeus; a smooth, 
shining, flattened space above the emargination extending almost to 
the base of the elypeus, the sides of the emargination porrect at 
the apex and produced over the mandibles. Head and thorax 
closely, finely and shallowly punetured, with long pale fulvous 
pubescence on the head and sides of the thorax; the antennae as 
long as the thorax and median segment combined, the apical joints 
arcuate. Scutellum sparsely and very finely punctured, strongly 
convex; with two obscure tubercles sometimes obsolete near the 
middle, thence oblique to the apex, which is rather broadly truncated. 
Postseutellum smooth and shining; the median segment very finely 
and shallowly punctured, narrowed posteriorly, with grey pubescence 
on the sides. Abdomen elongate, somewhat flattened, tapering at 
the extremities, shining and almost smooth, segments 2—5 with a 
slightly raised mark on each side close to the apical angles; hypo- 
pygium produced a little beyond the dorsal segment, not very 
narrow, ending in three short blunt spines or lobes, the central 
