SCHROTTKY | SOUTH AMERICAN HYMENOPTERA 267 
the base of the posterior tibiz which is yellow, are fulvous without 
any black. The abdominal segments at their apical margins are 
clothed with fine white hairs, which form indistinct fasciz laterally. 
The wings are hyaline, with brown nervures. 
Head densely covered with fine punctures; mesonotum with the 
punctures less dense but deeper and stronger ; the pleurze are covered 
with minute pale hairs and a few scattered but rather strong punc- 
tures. The base of the metathorax has irregular longitudinal folds 
or wrinkles, the truncation covered with pale hairs. The abdomen 
is impunctate, smooth and shining. Both recurrent nervures are 
interstitial. 
Taken in Villa Encarnacion, December 26 and 28, 1904. 
7. PROSOPIS RIVALIS new species 
Female.—Length, 6 mm.; abdomen, 1% mm. wide; wing, 4% 
mm.; antenne, 2 mm. long. Black; the clypeus, except the sides 
which are ferrugineous, is almost rectangular, a spot above it, the 
face on each side of the clypeus, the inner’orbits of the eyes nearly 
to their summit, the collar, the tubercles of the thorax, the tegulz in 
front, the scutellum, and the extreme base of the anterior and the 
posterior tibiz are yellow, the mandibles, the labrum, the antenne, the 
legs and the first abdominal segment, except a black patch on the 
apex of the dorsal face, are ferrugineous. Wings hyaline, the ner- 
vures fuscous. 
Head densely covered with fine punctures, the mesonotum with less 
dense but stronger punctures; the pleure have very fine, scattered 
punctures; the metathorax is truncate, the truncation covered with 
very fine pale hairs, and divided longitudinally by a shallow furrow, 
the basal area is longitudinally plicate, the sides covered with dense 
fine punctures; the abdomen is impunctate and polished, the apical 
margins of segments 2-5 being brown; near the base of the second 
segment is a low transverse depression. 
Taken at Villa Encarnacion on January 25, 1905. 
8. PROSOPIS. TRICOLOR new species 
Male.—Length, 6 mm.; abdomen, 1% mm. wide; wings, 4 mm.; 
antenne, 2mm. long. Black; the clypeus, a pentagonal spot above it, 
the face on each side of the clypeus, the inner orbits of the eyes nearly 
to their summit, the basal joint of the antennz in front, a transverse 
line on each side of the pronotum joining the tubercles of the thorax, 
and the tubercles, a spot in front of the tegulz, a spot on each side 
