ArT. 4, REVISION OF THE FAMILY THEREVIDAE—COLE. 99 
Abdomen black, brownish and gray pollinose, with short sparse 
while pile; last segment shining brownish black. Femora blackish 
brown, white pilose, the apices yellowish, as are the tibiae and tarsi; 
tibiae and tarsal joints with the apices brownish. Wings whitish 
hyaline, the stigma yellowish, the veins brown and yellowish; cell 
first A closed near the margin and M-3 closed in the margin. 
Type locality—Southern Pines, North Carolina, April 4, 1906 
(S. W. Foster), [Cornell]. 
Type.—temale, in the Cornell University collection. 
Paratypes._-The species should be easily recognized, and for this 
reason it is described from the poorly preserved type material. 
There are two female paratypes in the Cornell collection, taken in 
the type locality April 11, 1906. The facial spots are larger than in 
vialis and the antennae different, but it has undoubtedly been con- 
fused with this species by Kréber, who records vialis from North 
Carolina. 
THEREVA ALBOPILOSA Krober. 
1912. Thereva albopilosa Kro6ser, Stett. Ent. Zeit., p. 256. 
The following is a translation of the original description: 
Male.—Belongs to the group otiosa on account of the white abdominal pile. The 
pile is, however, not silvery white throughout, and the ground color is clearly percep- 
tible. The pile is very longand woolly. Face dense white pilose, so that the ground 
color is not visible. Frons with delicate, long, black pile, which reaches down to 
the lower corner of the eye. Antennae black; third joint brownish. Occiput whitish 
gray. Crown of bristles standing up from blackish brown, very long pile. Pile 
otherwise white, long, and wooly. Thorax opaque, without luster, through the 
mixed brown and white pile appearing peculiar gray, with two yellowish gray, indis- 
tinct, longitudinal stripes and a broad, blackish brown, median stripe. Pleura very 
thickly woolly white pilose. Halteres blackish brown, the stem somewhat lighter. 
Scutellum gray pollinose, white pilose. Abdomen in ground color black, almost 
opaque. Second to fifth segments with whitish yellow borders. Second to sixth 
with very broad yellowish gray pollinose bands. Seventh and eighth segments dull 
dark brown. Pile unusually long, pure white, on the reddish yellow anal lamellae 
yellowish. Venter yellowish gray pollinose. Second to fifth segments with yellow 
borders. Pile long, white. Femora blackish brown, with white pile; tibiae and 
tarsi yellowish brown, the tips somewhat darkened. Wings hyaline. Veins strong 
brown, the cross veins somewhat clouded. Stigma dark brown, large, deep colored. 
The fourth posterior cell closed. Length 12 mm. 
Type locality —Colorado. 
Type.—Male, in Kroéber’s collection. 
THEREVA COCKERELLI, new species. 
Plate 11, fig. 146. 
Male.—Length 9mm. Head black, the frons and face dense sil- 
very white pollinose and white pilose. Antennae black, with black 
bristles; the first two joints gray pollinose, the first joint with white 
pile on the basal half; style about one-fourth as long as the third 
60466—23—Proc. N.M.vol.62——20 
