IOWA ACADEMY OF SCIENCES- 



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that about Fayette, as each of these substrata bears its char- 

 acteristic lichens. As will be especially noted toward the 

 close of these notes, these two differences about offset each 

 other. The tamarack swamps about Minneapolis have no par- 

 allel about Payette, and furnish jichens not found, or rare, in 

 other parts of the former region. Yet all of these lichens 

 occur about Payette on one substratum or another, so that, in 

 the comparison, the former region will gain nothing. Minne- 

 apolis has the larger river and the lakes, but not a single 

 lichen has occurred near these bodies of water that is especially 

 characteristic of such localities. 



The following table, giving the genera and the number of 

 species in each for the Payette and Minneapolis vicinities, will 

 be instructive and will form the basis for some further compar- 

 isons of the two regions: 



The collecting at Payette extended over three years, and 

 that at Minneapolis only over two months. Yet the collecting 

 at the former place was my first extended work on lichens, and 

 the best part of the work was confined to a single summer. 

 The Payette column I have divided into two parts, the first 

 containing 157 species, which, with present experience, I should 

 expect to find in a region as favorable for lichen development 

 as Payette and in the time sf)ent in collecting at Minneapolis. 

 The second part of the Payette column contains 23 species, so 

 rare that one would not be so likely to find them in the short 

 time, or which are not found within five miles of Payette. The 



