The Hymenoptera of the Georgetown Museum. 221 
Polistes instabilis, Saus. 
Polistes pacificus, Fab. 
An exanple is probably a form of the above. The pleure are only slightly 
marked with black; the cloud in the costal cellule is more distinct than it is 
in the radial. 
Polistes quyanensis, sp. n. 
Ferraginois the face, front, vertex, upper half of the occiput, the middle 
of the mesonotum, broadly, the greater part of the scutellum and the apical 
4 abdominal segments, black ; wings fuscous violaceous, the apex from near the 
base of the radial cellule paler, the nervures black ; the following parts are 
bright yellow ; 2 broad curved line on the upper half of the sides of the clypeus; 
a line on the inner orbits, commencing a little above the eye incision, where it 
is narrowed, a line on the outer orbits, a narrow line round the edge of the 
basal slope of pronotum, a broader one round the top of the pleuree, 2 narrow 
lines down the middle of the mesonotum on the apical half, the basal third 
of the scutellum, a triangular spot outside this line, one on post-scutellum, 
narrowed in the middle, two broad curved lines on the metanotum, closer to 
each other above than below, a longish triangular spot on the mesopleure 
at the tubercles, the sides and apex of the 1st abdominal segment, an irregular 
spot, of moderate size, on the sides near the apex and narrow lines on the apices 
of the following 4 segments above, and more obscure lines below, bright 
lemon-yellow. Legs of 2 brighter ferruginous colour, the greater part of the 
4 anterior coxe, the hinder with a broad line on the sides above, bright lemon- 
yellow. Female. Length 15 mm. 
Potaro, May. 
Clypeus a little longer than wide, its apex gradually narrowed to a bluntiy 
rounded point. Malar space almost twice the length of the antennal pedicle. 
Ocelli in a triangle with the sides of the same length as the hinder part ; the 
hinder separated from each other by one fourth less than they are from the 
eyes. On the mesopleure a distinct, deep, curved keel runs down from the 
tubercles to near the middle ; on the lower half, near the centre, is a finer 
curved furrow. On the lower apical edge of the mesopleure, before the 
coxe, is a short, broad curved, yellow keel. 
— Odynerus pilosellus, sp.n. 
Black, the head, thorax ana basa] segment of the abdomen densely covered 
with long pale pubescence, the pubescence on the rest of the abdomen sparser 
and shorter, a mark near the apex of the clypeus wider than long, slightly 
roundly narrowed towards the apex, which is roundly incised in the centre, 
the sides forming rounded lobes, a short longitudina! line between and above 
the antenne, a curved line on the apex of the pronotum, the apex of tegule 
and moderately broau lines on the apices of the basal 5th abdominal seg- 
ments all round, the last ventral almost entirely, bright lemon yellow ; wings, 
light fuscous violaceous, the hinder paler; the anterior tarsi with the apical 
joint piccous. Female. Length 10 m.m. 
Costa Rica. 
