508 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 118 
acters are concerned. JI have examined European specimens of S. 
nemorum (Meigen) and find these indistinguishable from the North 
American forms. Thus I would consider the North American mate- 
rial which I have examined to be S. nemorum (Meigen). 
Loew (1862a) described S. assimilis from North America, and 
Czerny considered this species to be distinct from S. nemorum 
(Meigen). I have examined Loew’s type (a male) in the Museum 
of Comparative Zoology at Harvard University. It agrees with 
European specimens of S. nemorum (Meigen). 
Steyskal (1944) included both S. assimilis (Loew) and S. nemorum 
(Meigen) in his key to Suillia. The character used by Steyskal to 
separate the two forms was the presence or absence of a crossband 
in the upper third of the eye in living specimens. The crossband 
was said to be present in S. nemorum (Meigen) but absent in S. 
assimilis (Loew). Although the crossband is not present in dried 
specimens, I have found that in relaxed specimens the crossband is 
restored, both in American and European forms. 
Aldrich (in Aldrich and Darlington, 1908, p. 93) agreed, as shown 
by the following quotation, that these two species are synonymous: 
Loew did not identify nemorum from North America, but named our species 
assimilis, stating that it did not differ from nemorum, except in having a little 
shorter plumosity of the arista and general paler color; Czerny identified his 
American material as nemorum, and did not identify ass¢milis, merely quoting 
the description. . . . From these facts I feel safe in making assimilis a synonym 
of nemorum. 
DistriputTion.—Alaska, western Canada, and western United 
States as far south as Arizona and New Mexico; eastward through 
Montana, South Dakota, Minnesota, Michigan, Ontario, Quebec, 
and Vermont; May—October. 
Genus Allophyla Loew 
Allophyla Loew, 1859, p. 438; 1862b, p. 127.—Aldrich and Darlington, 1908, 
p. 98.—Czerny, 1924, p. 63; 1927a, p. 21. 
This genus bears a general resemblance to Swillia, but is easily 
separated from it by the presence of a strong humeral bristle in 
Allophyla. The humeral bristle is absent in Swillia. 
Contrary to the description of Aldrich and Darlington (1908), 
there is no propleural bristle in Allophyla. 
Key to the species of Allophyla 
Antennavelblack. 4 wes at een en tenia A en TAS, Ai ke atricornis Meigen 
Antennae yellow (third segment may be darkened). . ... . . . laevis Loew 
