518 PROCEEDINGS OF THE NATIONAL MUSEUM VOL, 113 
Lrenetu.—4.0—5.0 mm. 
DistripuTion.—Alaska, British Columbia to Newfoundland, south 
to California, Colorado, North Carolina. Collections have been 
made during every month of the year. 
BioLtoagy.—This species has been reared from immature stages in 
a potato, according to the label on a specimen in the U.S. National 
Museum. It was reported by Howard (1900) on human excrement 
and by Saunt (1934) from birds’ nests. In the Canadian National 
Collection a series of 10 males and 5 females is recorded from Spirea, 
and 1 female was “bred from larva in Dicrostonyx burrow.” 
ReMARKS.—It will be noted that strict observance of page prec- 
edence would give Helomyza canescens Meigen priority over H. 
rufiventris Meigen. Loew (1859) was chronologically the first to 
utilize either of Meigen’s names. Loew used Tephrochlamys ru- 
fiventris (Meigen), but was probably not aware of its synonymy with 
H. canescens Meigen. Thus, Aldrich and Darlington (1908) are 
actually the ‘“‘first revisers,’’ and they clearly indicated that they 
recognized the synonymy and were in favor of retaining Tephrochlamys 
rufiventris (Meigen) as the name for this species. 
Tephrochlamys flavitarsis Darlington 
Tephrochlamys flavitarsis Darlington, in Aldrich and Darlington, 1908, p. 71.— 
Czerny, 1924, p. 83. 
I have examined the type female in the U.S. National Museum 
(Type 11978). It agrees very closely with Tephrochlamys rufiventris 
(Meigen), except that the scutellum and legs are wholly yellow. ‘The 
type is labelled “White Mts., Morrison.” 
MALE AND FEMALE.—Head similar to 7. rufiventris (Meigen), 
except that orbito-antennal spot is less distinct; cheek-eye ratio 
from 0.35 to 0.55. 
Mesonotum ash gray with 2 dark brown vittae between the dorso- 
centrals and a broader, discontinuous vitta lateral to each row of 
dorsocentrals; humeri and scutellum yellowish; pleura ash gray to 
brownish, may show a yellowing in some areas; chaetotaxy as in 
rufiventris. 
Legs wholly yellow or slightly darkened on forefemora and tarsi; 
wings and abdomen as in rufiveniris. 
Lrenotu.—4.0—-5.0 mm. 
DistRrBution.—British Columbia, Ontario, North Carolina, New 
Hampshire, Quebec, New Brunswick, Nova Scotia; April-August. 
Genus Aecothea Haliday 
Helomyza Fallén, 1820, p. 3 (part).—Meigen, 1830, p. 47 (part).—Zetterstedt, 
1847, p. 2480 (part). 
