133 
All of our species have four postsutural and four sternopleural inacro- 
cliaetse, and at most with, only two marginal iuacroclueta % on the first 
segment of the abdomen; hind tibiae outwardly ciliate, two pairs of 
orbital bristles in both sexes: 
1. Third joint of antenna?, except sometimes the base, black 2. 
Third joint of antennae deep yellow; otherwise as in capitata; lengthy 
11 to 13 mm. Maryland; St. Louis, Mo., and Georgia. (Cana- 
dian Entomologist, Vol. XIX, p. 10; January, 1887. Gonia 
sagax Townsend, Canadian Entomologist, Vol. XXIV, p. 05; 
March, 1892.) senilis Will. 
2. Viewed from the side, the head projects in front of the eye only 
slightly more than the horizontal diameter of the eye, and is 
sparsely covered with bristly hairs; sides of front, when viewed 
from behind, shining, destitute of pollen except next the eyes; 
abdomen black, the sides sometimes partly or wholly reddish or 
yellow, bases of last three segments gray pollinose; length, to 
14 mm. Toronto, Canada; Beverly, Mass.; Oswego, X. Y. ; 
District of Columbia; Xorth Carolina; Georgia; Detroit, Mich.; 
Illinois; Ames, Iowa; Missouri: Sunnyside, Ark.; Kansas; 
Texas; Colorado; California; Pullman, Wash., and Austria. 
A male specimen from Austria received from Brauer and Ber- 
genstamm and by them labeled Oonia capitata DeGeer. 1 (Me- 
moires servir FHistoire Insectes, Vol. VI, p. 12; 1770: Mtisca. 
Gonia frontosa Say, Journal Acad. Xat. Sci. Phila., Vol. VI, 
p. 175; 1829. Gonia philadelphica Macquart, Dipteres Exo- 
tiques, Vol. II, Part III, p. 208 [51]; 1842. Gonia albifrons 
Walker, List of Dipterous Insects, Part IV, p. 798; 1849. 
Gonia exul Williston, Can. Entomologist, Vol. XIX, p. 11; Jan., 
1887. Gonia sequax Williston, loc. cit., p. 12.) .capitata DeGeer. 
Viewed from the side, the head projects in front of the eye almost 
twice the horizontal diameter of the eye and is densely covered 
with bristly hairs; sides of front when viewed from behind 
wholly covered with white pollen ; black, the front, including 
the vitta, the face, cheeks, palpi, humeri, hind end of thorax, 
scutellum, and sides of the first three segments of the abdomen 
except the hind' margin of the third, yellow; front in profile 
only slightly convex, almost at right angles to the occiput, in 
the male two and one-half times as wide as either eye, frontal 
bristles descending to base of second antennal joint, two or 
1 The synonymy of this species in Europe is very uncertain and unsatisfactory. It 
will doubtless he found that ornata Meigen and fasciata Meigen are hut colorational 
forms of capitata DeGeer. Our specimens of the latter from this country show every 
possible gradation from those with the abdomen wholly black to those that have it 
yellow and marked with a narrow black dorsal vitta. A female having the abdomen 
wholly black except a small yellowish spot on each side of the second segment was 
taken united in coition to a male in which the sides of the first three segments were 
almost wholly yellowish. 
