Fink: LICHENS OF NORTHWESTERN MINNESOTA. 673 



The lichens composing the smooth bark formation are not so 

 various in type, including only the more crustaceous and rudi- 

 mentary types of those given above. The more developed 

 forms with more specialized rhizoids usually fail to gain a foot- 

 hold on the smooth bark. 



Next in order may be considered the formation of old wood. 



CALICEI LICHEN FORMATION OF DEAD WOOD (BEMIDJl). 



Placodium cerinum (HEDW.) NAEG. and HEPP. var. pyracea 

 NYL., C. 



Placodium ferrugineum (Huos.) HEPP. 



Lecanora varia (EHRH.) NYL., C. 



Lecanora varia (EHRH.) NYL. var. ssepincola FR. 



Lecanora varia (EHRH.) NYL. var. symmicta ACH. 



Rinodina sophodes (Acn.) NYL., C. 



Biatora uliginosa (SCHRAD.) FR. 



Lecidea enteroleuca FR. var. ambigua ANZ. 



Buellia parasema (Acn.) TH. FR., C. 



Buellia myriocarpa (DC.) MUDD. 



Acolium tigillare (Acn.) DN. 



Calicium lucidum (Tn. FR.) FINK. 



Calicium sp. 



Calicium trabinellum (SCHAER.) KBR. 



Calicium parietinum ACH. 



Calicium trichiale ACH. var. cinereum NYL. 



This formation is given a slightly different designation from 

 the similar ones previously recorded for Mankota and Granite 

 Falls * because of the absence of old boards in the new country 

 about Bemidji. The formation recorded in this paper is similar 

 to the two formerly recorded, but much richer, especially in 

 Calicei, for which group the formation is named. Yet the 

 three Calicei formations recorded for the state show more varia- 

 tion than other related formations and have only four (C) com- 

 mon species of a total of 23. Moreover, not a single member 

 of the Calicei is common to the three formations. From some 

 hasty observations made in 1897 in the Lake Superior region, \ 

 I had come to believe that certain Caliciums normally grow on 

 rotting wood. Careful observation in 1900 showed that all 



*Fink, B. 1. c., 305-306. 

 fFink, B. 1. c., 306. 



