SCHROTIKY] SOUTH AMERICAN HYMENOPTERA 263 
notum is unicolorous black; the tubercles of the thorax are sometimes 
dark fuscous and sometimes black. The semicircular pale yellow line 
exists only in the first described specimen. The honey-color of the 
anterior tibiz is sometimes reduced to the basal half, sometimes it 
disappears entirely. One of the specimens has a rather distinct fascia 
of white hairs on the apical margin of the second abdominal segment, 
and in another the fine hairs on the abdominal segments are whitish. 
But as the color of the scutellum and the postscutellum is always 
bright yellow, the species may be easily distinguished from all others 
by this character and by the comparatively larger size. 
To judge from the few specimens I have seen, the darker form 
seems to be the commoner, while the other is perhaps merely a form 
immaturely colored. The morphological structure is identical in both 
forms. 
The species appears to be rare. 
3. PROSOPIS GUARANITICA new species 
Male.—Length, 6 mm.; abdomen, 1% mm. wide; wings, 4 mm.; 
antenne, 244 mm. long. Black; the clypeus, a nearly triangular spot 
above it, the face on the sides of the clypeus, the inner orbits of the 
eyes reaching upwards nearly to their summit, the tubercles of the 
thorax, and the scutellum, are bright yellow; the antennz are fer- 
rugineous in front and fuscous above; pronotum with two orange- 
red spots; tegule brownish, with a minute yellow spot; the apical 
margins of the abdominal segments are fringed with minute white 
hairs, but they form no conspicuous fasciz ; the whole anterior tibiz 
and tarsi, the intermediate tibiz at their base and apex and the 
posterior tibiz at base are yellow; the wings are hyaline, with a 
fuscous cloud occupying the marginal cell and extending to the apex 
of the wing; in the first cubital cell as well as in the apex of the 
median cell the cloud becomes less pronounced. 
Head densely punctured; mesonotum and pleure covered with 
deeply impressed punctures; metathorax truncate, the truncation in 
the middle depressed and covered with radiating plicz ; basal space in 
the middle with two low longitudinal carinez, at the sides of which 
is a smooth space, surrounded by a distinct oval impression. The 
first abdominal segment is densely and deeply punctured; second 
segment with a deep basal depression, covered with fine and very 
numerous punctures except on its apex. The neuration of the wings 
is the same as in P. polybioides. 
Taken frequently in December, 1904, and January, 1905, in Villa 
Encarnacion, Paraguay. 
