121 
Third vein bearing only two bristles at the base, front of the male 
one and one-half times as wide as either eye; yellow, the third 
antennal joint, proboscis, center of dorsum of thorax, three 
spots on the pleura, and a dorsal spot on the third and fourth 
segments of the abdomen black; frontal bristles descending 
almost to apex of second antennal joint, third autennal joint 
twice as long as the second, arista thickened on the basal third, 
cheeks nearly one-half as wide as the eye height, proboscis slen- 
der, rigid, labella very small; second and third segments of abdo- 
men bearing marginal macrochietie, the fourth covered except 
on the basal third; wings hyaline, calypteres white; front pul- 
villi slightly shorter than the last tarsal joint; length, 11 mm. 
Denver, Colo. A single male specimen. Type in U.S. National 
AUIS CSU DT SR ES el Re eee eG eee eae pallidus 0. sp. 
3. Scutellum yellow, four postsutural and four sternopleural macro- 
chete; black, the first two joints of the antennie, the palpi, 
scutellum, and sides of the last three abdominal segments, also 
the apex of the fourth, yellow; front in female slightly wider 
than either eye, frontal bristles descending almost to tip of 
second antennal joint, antennie nearly three-fourths as long as 
the face, the third joint one and one-fourth times as long as the 
second, arista thickened on the basal three-fifths, the penulti- 
mate joint one and one-half times as long as wide; head at base 
of antenne slightly shorter than on its lower edge, vibrisse 
inserted about half the length of the second antennal joint 
above the oral margin, three or four bristles above each; thorax 
gray pollinose, marked with four black vitte; scutellum bearing 
four pairs of rather long marginal macrochietie ; abdomen thinly 
gray pollinose, second segment bearing a pair of marginal ma- 
crochete, the third bearing a marginal row, the fourth covered 
except on the basal fifth; middle tibiw each bearing two long 
macrochete on the front side near the middle, the hind tibiz 
outwardly subciliate; wings hyaline, third vein bearing about 
four bristles near its base, the others bare, apex of third vein mid- 
way between tip of second and the extreme wing tip, hind cross- 
vein at last third of distance from the small to the bend, the 
latter not appendiculate; calypteres white; length, 8 mm. Siski- 
you Co., Cal. A female specimen bred from Melitwa palla by 
A. Koebele. Type No. 3626, U.S. National Museum. melitee@ n. sp. 
Seutellum black, probably four postsutural macrochetie, but the 
anterior pair is wanting in the type specimen, four sterno- 
pleurals; black, the palpi, sides of first three segments of abdo- 
men except the front corners, tibiw, and apical third of under 
side of each femur yellowish; front of male one-half as wide as 
either eye, no orbital bristles, frontals descending to middle of 
second joint of antennie, cheeks one-third as broad as the eye- 
