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Fink: LICHENS OF NORTHWESTERN MINNESOTA. 663 
as compared with northeastern Minnesota extends to genera as 
well as to species, so that 36 genera were found in the former 
area and 39 in the latter. This would be expected when we 
notice that all the seven northern species recorded above belong 
to genera occurring in the southern half of Minnesota, while 
the four genera named above as not occurring in northwestern 
Minnesota also have no representatives in the southern half of 
the state, being for the most part the most strictly northern gen- 
era thus far found in Minnesota. 
The summer’s collecting brought to light 48 species and va- 
rieties new to the state, of which 9g are new to North America 
and 3 new, while another 3 are yet undetermined. The dis- 
covery of so large a proportion of new material nearly one- 
fourth of all species collected, after other parts of the state had 
been for the most part, well studied, is somewhat of a surprise, 
and seems to indicate that there is yet a good number of lichens 
to be found in Minnesota. As to forms new to North America, 
this paper adds a larger number than all the previous lists pub- 
lished for the state. 
The genus Caliccum deserves special mention because of the 
interesting facts disclosed when the material collected was care- 
fully studied. Previously nine species and varieties had been 
recorded for the state, and though the genus is not an arctic or 
subarctic one, I had not expected to find it well represented in 
territory otherwise closely related to the southern half of Minne- 
sota as to lichen population. Consequently, I was not a little 
surprised to find ten species in my collection, one more than had 
hitherto been reported for the state, and yet more when I found 
that six of the species were new to the state, thus raising the 
number of Calzccwms in Minnesota to 15 species and varieties. 
We now have found within the state about half of the forms of 
the genus recorded for North America, and Caliczum can no 
longer be regarded as a genus peculiar to the Atlantic region. 
The cause of the extension of members of the genus into a re- 
gion closely related with southern Minnesota as to lichen flora 
is to be found in the circumstance that the Calczwms seem to 
follow the conifers regardless of slight climatic changes. While 
some other genera furnish each a few species new to the state, 
or not found further south in Minnesota, there is nothing espe- 
cially noteworthy about the distribution of any of them, as the 
species are in general such as could be expected to occur farther 
south, and may have been overlooked. 
