Fink: LICHENS OF NORTHWESTERN MINNESOTA. 691 
819 and July 21, 1900, no. 855. Some have very heavy 
-thallus. 
66. Placodium cerinum (Hrepw.) Narc. and Hepp. 
On trees and granite rocks, frequent or infrequent. Battle 
lake, June 18, 1900, no. 13, June 19, 1900, no. 30, June 20, 
1900, no. 73 and June 23, 1900, no. 164. Henning, June 25, 
1900, nos. 177 and 199. Leaf hills, June 26, 1900, no. 244 
and June 27, 1900, nos. 267 and 271. Henning, June 28, 
1900, no. 321. Bemidji, July 4, 1900, no. 454, July 5, 1900, 
nos. 459 and 465 and July 11, 1900, no. 644. Thief River 
Falls, July 17, 1900, nos. 756 and 775, July 19, 1900, nos. 
817, 818 and 823, July 20, 1900, no. 835 and July 21, 1900, 
no. 861. Red lake, July 26, 1900, no. 883, July 28, 1900, 
no. 953, July 30, 1900, no. 979, Aug. I, 1900, no. 1025 and 
Aug. 2, 1900, no. 1061. 
67. Placodium cerinum (HEpw.) Narc. and Hepp. var. sidiritis 
Tuck. 
On granite rocks, infrequent. Battle lake, June 20, 1900, 
no. 68, and June 23, 1900, nos. 149 and 157. Leaf hills, June 
27, I900, nos. 247 and 263. Red lake, July 31, 1900, no. 
IOIl. 
68. Placodium cerinum (HEpw.) Narc. and Hepp. var. pyracea 
INYd:. 
On pine logs, frequent. Red lake, July 30, 1900, no. 983. 
69. Placodium ferrugineum (Hups.) Hepp. 
On old pine, frequent. Bemidji, July 15, 1900, no. 705. 
Red lake, July 30, 1900, no. 976. 
70. Placodium vitellinum (Euru.) Nare. and Hepp. 
On old wood and granite rocks, rare. Battle lake, June 20, 
1900, no. 104. Leaf hills, June 26, 1900, no. 240 and June 
27, 1900, no. 278, Bemidji, July 10, 1900, no. 559. Red 
lake, July 28, 1900, no. 960 and July 30, 1900, no. 982. 
71. Placodium vitellinum (Enru.) NArEGc. and Hepp. var. 
aurellum Acu. 
On trees and granite rocks, infrequent. Battle lake, June 
20, 1900, no. 56. Leaf hills, June 26, rg00, no. 251a and June 
27, 1900; no. 257. Bemidji, July 11, 1900, no. 639. 
