262 ENTOMOLOGICAL SOCIETY 
flies, and for that very fact necessarily contains little that is strictly orig-* 
inal." 
Lintner, treating the same species, calls attention to Packard's state- 
ment, adding that it is the only record known to him of the species occur- 
ring in the fall, and that it has never come under his own observation at 
that time. Writing for information to Mr. E. L. Keen, of Philadelphia, he 
received the replv that Mr. Keen had never seen the species after July, but 
had taken " a few specimens of a small black species of Bibio* in a shel- 
tered ravine " in October. 
In regard to European species : 
Meigen says that the time of appearance of these flies is, with the excep- 
tion of Bibio clavipes, in the spring. Of that species he writes: "Very 
common in October and November on bushes. It is remarkable that, 
while all other Bibios known to me appear in the spring, this should make 
its first appearance in late autumn." Walker records it autumnal in 
Great Britain. 
Zetterstedt, in treating the Scandinavian species, makes clavipes the 
only exception to their spring and summer occurrence, and says that it is 
" very common on grasses and fruit tree foliage toward autumn (August- 
October) through all Scandinavia, the Lapland mountains excepted." 
Siebke, in his Diptera of Norway, says that clavtpes occurs from June 
to September, which is a much earlier date than given by other authors. 
If these accounts are put together the dates would stretch from June to 
November, and allow the possibility of two appearances running into each 
other. 
The European pomonce is stated by Walker to be both vernal and au- 
tumnal in Britain. Meigen, however, says that it occurs in June and July, 
while Siebke says June to August. 
As to fall occurrences of the nearly allied Dilophus, these have come 
more directly under my notice. On the yth of November, about noon, the 
day being bright and clear but somewhat chilly, I secured 13 specimens of 
Dilophus from the shady (north and east) sides of the Washington Mon- 
ument, near its base. The sunny (south and west) sides of the shaft were 
first examined, with no other result than the discovery of specimens of the 
Cluster Fly (Pollenia rudis] and a few large Muscids, which seemed to 
be the only insects that could stand the glare of the sun on the smooth, 
white surface. These Dilophus were of two species. Eleven specimens, 
ten 9 $ an d one <5\ are near D.- serotinus Loew; the others are two <$$, 
entirely black and with the wings very dark smoky. Three specimens of 
a species very near the former, perhaps the same, were taken by Mr. Mar- 
latt in this vicinity on the 5th of May last. Therefore this species prob- 
ably occurs both in spring and fall. 
As a last notice of specimens collected in the fall, I will mention that in 
the National Museum collections there are no less than 36 specimens of 
*This was probably a Dilophus. "I. T. 
