176 BULLETIN OF WISCONSIN NATURAL HISTORY SOCIETY. VOL. 1. NO. 3. 
very extended range of distribution, occurring in America, 
Europe, Asia and Africa. Among the species, which have never 
been observed outside of the American continent, the following 
five are inhabitants of North America and of South America 
besides: Chrysogasfer nitida, Wied, Allograpta ohliqua, Say., 
Mesograinma geminata, Say., Eristalis meigenn, Wied., and 
Eristalis vinctonim, Fahr. Several of our species occur as far 
north as Alaska, Hudson's Bay Territory and even Greenland, 
as for example Microdot tristis, Loew., Platychirus hyperboreus, 
Staeg.,- Syrphus arciiatiis, Fall., Syrphns torvus, 0. S., Syrphus 
lesueurii, Macq., Syrphus uinhellatarum, 0. S., Sericomyia mili- 
taris, Walk, and Xylofa ejiincida, Say. 
The foregoing remarks on the geographical distribution of 
our species are based on the present standing of our knowledge 
of the subject. A careful study of the flies, belonging to this 
family, at difl:'erent points of our continent, as well as of other 
continents, will certainly result in materially changing our views 
on the distribution of the species. Even in our own country, 
relatively little work has been done in this direction in most of 
the states, and this accounts for the fact, that several species, 
figuring on our list, have up to the present time been recorded 
only from regions, situated at a great distance from our locality. 
This is the case with Microdon tristis, Loew., our two species of 
Neoascia, Baccha clavata, Fahr., Helophihis distinctus. Will., 
Crioprora cyanogaster, Loew., and other species. 
In determining the species, I have relied almost exclusively 
on Williston's ''Synopsis of the N. Am. Syrphidae," referred to 
above, and have gained much information, regarding the geo- 
graphical distribution of the species therefrom. Besides, I have 
Had access to the following papers : 
1. Chas. Robertson. Flowers and insects. Nos. I to XVIII, 
published in the Botanical Gazette. Vol. XIV, May 
1889 to Vol. XXV, April 1898. 
Five additional papers of the same series appeared 
in Vol. V, Nos. 3 and 4, Vol. VI, Nos. 4 and 14 and 
Vol. VII, No. 6 of the Transactions of the Academy of 
Science of St. Louis. 
2. W. D. Hunter. A contribution to the knowledge of North 
American Syrphidae. Paper No. I in the Canadian 
Entomologist, Vol. XXVIII, No. 4, April 1896; Paper 
No. II in the Canadian Entomologist, Vol. XXIX, No. 
6, June 1897. 
