JULY, 1900. GRAENICHER— THE SYRPHIDAE OF MILWAUKEE COUNTY. 169 
12. Platychirus quadratus, Say. A common species, occurring 
from May (on flowers of Saxifraga Pennsylvanica, L.) 
to x\ugust (on umbels of Sium cicutae folium, Gmelin). 
Previously reported for the Eastern, Middle and 
Pacific States. 
13. Platychirus hyperboreus, Staeg. Not common. From July 
to September, preferably on the flowers of umbellifer- 
ous plants (Oxypolis rigidus, fL.J Britt., and Coniose- 
liniini Chinense (L.) B. S. P.) 
Has been reported for the Atlantic States, Illinois 
Colorado and for Greenland. 
14. Platychirus peltatus, Meig. Rare. 2 ? specimens taken in 
June. 
Inhabits Europe and North America. Has been 
reported for a few Atlantic States and Alaska. 
15. Syrphus arcuatus. Fallen. Rare, i 9 taken in September. 
Occurs in Europe and North America and has been 
observed throughout the northern part of the United 
States, from the Atlantic to the Pacific coast, extending 
its range southward as far as Colorado and north vvartl 
to Hudson's Bay Territory and Nova Scotia. 
16. Syrphus ribesii, L. Very common throughout the season, 
from April (on catkins of Salix discolor, Muhl.) to 
October (on flowers of Hainamelis Virginiana, L.) 
Inhabits Europe and North America, from the 
Atlantic to the Pacific States, south to Arizona, north 
to Canada. 
17. Syrphus toryus, O. S. Not common. Taken in Septem- 
ber and October on flowers of Aster laevis, L. 
* Inhabits Europe, North America and Siberia. Has 
been recorded from various points of this continent, 
from the Atlantic to the Pacific coast, south to Colorado 
and north to Greenland. 
18. Syrphus lesueurii, Macq. Rare. A single specimen 
captured in June on the umbels of Cicuta macidata, L. 
Previously recorded from the New England States, 
Washington and Alaska. 
19. Syrphus americanus, Wied. An abundant species through- 
out the season, from April (on catkins of Salix disco- 
lor, Muhl.) to October (on flowers of Hamamclis Vir- 
giniana, L.) 
Has been recorded from the Atlantic States to Mon- 
tana, from Canada and Texas. 
