45 
3. Females; genitalia awl shaped, directed backward 4. 
Males; genitalia tubular, directed forward under the body; black, 
the palpi yellow, abdomen with a pronounced brassy tinge, 
shining, thinly white pollinose ; thorax when viewed from behind 
thinly white pollinose except the front end and two subdorsal 
vittae behind the suture; eyes separated as widely as the posterior 
ocelli, calypteres grayish white, wings whitish hyaline, base to 
tip of second basal cell yellow, costa strongly arcuate, last 
section of third vein nearly half as long as the preceding sec- 
tion ; length, G mm. Potomac Creek, Virginia. A single male 
specimen collected May 23, 1896, by G. W. Johnson. Type No. 
3520, U. S. National Museum nitida n. sp. 
4. Frontal vitta at narrowest part less than one-third as w T ide as the 
distance between the posterior ocelli 5. 
Frontal vitta at narrowest part as wide as the distance between the 
posterior ocelli; last section of third vein slightly over one-third 
as long as the preceding section ; length, 4 to 6 mm. White 
Mountains and Franconia, X. II., and Potomac Creek, Virginia. 
(Trans. Amer. Ent. Soc, Vol. XIII, p. 296; October, 1886: 
Ilyalomyia.) ceneoventris Will. 
5. Last section of third vein over one third as long as the preceding 
section, small cross vein nearer to tip of first vein than to tip of 
the auxiliary, or midway between them; black, the palpi yellow; 
thorax, when viewed from behind, subopaque whitish pollinose, 
with indistinct black vitta 1 ; eyes separated slightly wider than 
width of lowest ocellus; face white or gray pollinose; abdomen 
on the last three segments whitish pollinose, the second and 
third segments with a black dorsal vitta; calypteres whitish or 
yellowish; wings hyaline, the base to slightly beyond the hu- 
meral crossvein yellowish; length, 9 mm. Beverly, Mass. A 
female specimen collected October 11, 1870, by the late Edw. 
Burgess. Type No. 3521, U. S. National Museum, .diversa n sp. 
Last section, etc., as above; vitta of abdomen indistinct; length, 
5 mm. Two females, one captured at Sherbrooke, Canada, Sep- 
tember 25, 1896, by L'Abbe P. A. Begin, the other taken with 
the male (see above under 3) nitida n. sp. 
Last section of third vein less than one-sixth as long as the preeed 
ing section, small crossvein nearer to tip of auxiliary vein than 
to tip of first vein; eyes separated about half the width of the 
lowest ocellus; face yellow pollinose, abdomen wholly thinly 
whitish pollinose; length, 9 to 10 mm.; otherwise as in diversa. 
Lufkin, Tex. (October 17, 1894; C. W. Johnson), and southern 
Illinois (Charles Robertson). Two female specimens. Type No. 
3522, U. S. National Museum grandis n. sp. 
