ART, 4. REVISION OF THE FAMILY THEREVIDAE—COLE. 43 
Frons shining black, silvery pollinose on the lower corners. Antennae 
black, the third joint slightly longer and wider than the first. 
The dorsum of the thorax lacks the distinct, dark, median thoracic 
stripe; pile of the dorsum reclinate and golden, very dense on the 
scutellum and the space in front of it. Pleura as in haemorrhoidalis 
and related species. Stem of halteres and base of knob brown, the 
rest of the knob yellowish brown (not bright yellow as in aldrichi or 
blackish as in haemorrhoidalis). Genitalia reddish, most all of the 
pile black (fig. 107 for structure). Wings yellowish hyaline, the 
veins yellowish brown; apex of the wing gray, the stigma yellow; cell 
M-3 closed. Legs as in haemorrhoidalis. 
Female.—Distinguished from the female of haemorrhoidalis by the 
more apparent, short, tomentumlike golden pile on the thorax and 
scutellum, also by the pale-brown knobs of the halteres and the paler 
wing veins. The wings are darker than in the male, in some speci- 
mens with pale-brown infuscated areas; stigma yellowish. The frons 
is almost identical with haemorrhoidalis (fig. 17¢c), but the vertex and 
ocellar tubercle are shining instead of thinly gray pollinose. 
Type locality.—Cupids Bower Island, Maryland, July 8 and 4, 1915 
(R. C. Shannon). 
Type.—Male, Cat. No. 25931,.U.S.N.M. 
Paratypes.—These consist of 11 males and 19 females, as follows: 
Massachusetts: Woods Hole, July 18 (W. M. Wheeler), [Amer. 
Mus.]; Horseneck Beach, July 30 [B. S. N. H.]. 
Rhode Island: Buttonwoods, July 21 [B. S. N. H.]. 
New Jersey: Weymouth, August 16 (Daecke); Newbold, July 21 
(Daecke) ; Stone Harbor, August 3 (Daecke); Lacy, July 22 (Daecke) ; 
Malaga, July 27 (Daecke), [all Harrisb. coll.]; Lakehurst, July 4 
(C. E. Olsen); Clementon, August 8; Anglesea, September 1; James- 
burg, July 31 (C. W. Johnson), cotype of P. aldricht Coquillett, 
Riverton, August 1 to 28 (C. W. Johnson), [all C. W. Johnson]. 
New York: ‘‘ New York” [M. C. Z.]. 
Pennsylvania: Rockville, July 23 (Daecke),[Harrisb. coll.]; Natrona, 
July 30, and Philadelphia, July 22 [C. W. Johnson]. 
Virginia: Falls Church, July 17 and 25 (N. Banks), [Cole]; Falls 
Church, July 13 (Knab), [Biol. Surv.]. 
Maryland: Plummer Island, at light, August 3 (R. C. Shannon), 
[Cole]; Cupids Bower Island, July 8 (R. C. Shannon), [U.S.N. M.]; 
Plummer Island, July 14 to August 3 (R. C. Shannon), [Shannon]. 
PSILOCEPHALA NOTATA (Wiedemann). 
Plate 7, fig. 75; and plate 8, fig. 85. 
1821. Thereva notata WIEDEMANN, Dipt. Exot., p. 114. 
This species is in the haemorrhoidalis group. The writer agrees 
with Mr. C. W. Johnson in his determination of this species, the 
