704 MINNESOTA BOTANICAL STUDIES. 



168. Buellia alboatra (HOFFM.) TH. FR. 



On trees, rare. Battle lake, June 21, 1900, no. 117 and 

 June 25, 1900, no. 158. Bemidji, July u, 1900, nos. 679 and 

 687. Thief River Falls, July 23, 1900, no. 872. Red lake, 

 July 27, 1900, no. 965. 



169. Buellia parasema (Acn.) TH. FR. 



On trees, infrequent. Leaf hills, June 27, 1900, no. 272. 

 Bemidji, July 4, 1900, no. 434, July 7, 1900, nos. 510, 511 and 

 542 and July 12, 1900, nos. 662 and 696. Thief River Falls, 

 July 20, 1900, no. 831. Red lake, July 28, 1900, no. 939, 

 July 30, 1900, no. 939 and August 2, 1900, no. 1056. 



170. Buellia myriocarpa (DC.) MUDD. 



On pines, rare. Battle lake, June 19, 1900, no. 23. Bemidji, 

 July 5, 1900, no. 488. Red lake, August 2, 1900, no. 1059. 



171. Buellia myriocarpa (DC.) MUDD. var. polyspora WILLEY. 

 On cedar in swamps, rare. Bemidji, July 13, 1900, no. 714. 



172. Buellia pullata TUCK. ? 



On granitic rocks, infrequent. Leaf hills, June 26, 1900, 

 no. 241. 



Spores 9-14 mic. long by 6-7.5 m ^ c - wide, and thallus 

 scanty. 



173. Buellia petraea (FLOT., KBR.) TUCK. 



On exposed granitic rocks, locally frequent. Battle lake, 

 June 23, 1900, no. 158. Leaf hills, July 2, 1900, no. 386. 



174. Buellia petraea (FLOT., KBR.) TUCK. var. montagnaei 

 TUCK. 



On exposed granitic rocks, locally common. Battle lake, 

 June 20, 1900, no. 62 and June 23, 1900, no. 169. Leaf hills, 

 June 27, 1900, nos. 283 and 294 and July 2, 1900, no. 396. 



175. Melaspilea arthonioides (FEE) NYL. 



On trees, rare. Battle lake, June 21, 1900, no. 122 and 

 June 22, 1900, no. 133. Bemidji, July n, 1900, no. 604. Thief 

 River Falls, July 21, 1900, no. 849. 



Not previonsly reported from Minnesota. 



176. Opegrapha varia (PERS.) FR. 



On trees, common. Battle lake, June 18, 1900, nos. 15 and 

 17 and June 19, 1900, nos. 29 and 32. Henning, June 25, 1900, 

 no. 176 and June 30, 1900, no. 362. Bemidji, July 4, 1900, no. 



