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 9 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 Calicium 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 Caliciums 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 Calicium 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 Caliciums 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. 



