Fink : Lichen Distribution in North America 305 



Physcia comosa (Eschw.) Nyl. 



Near Little Rock, Arkansas, Coll. Colton Russell, 1899, bark. 

 Physcia hispida (Schreb.) Tuck. 



San Juan Island in Puget Sound, 1906, old fences. 

 Physcia pulverulenta (Schreb.) Nyl. 



Waldron Island in Puget Sound, and near Glacier, British Columbia, 1906, 

 rocks. 



Physcia teretiuscula (Nyl.). 



Gunflint, Minnesota, 1897, Hot Springs, Arkansas, Coll. Colton Russell, 

 1899, and Iron County, Missouri, by the same collector, 1900, rocks. 

 Little known in North America, being usually confused with Physcia 

 caesia (Hofifm.) Nyl. 

 Piloporus aciculdris (Ach.) Th. Fr. 



San Juan Island in Puget Sound, 1906, rocks. 

 Piloporus hallii (Tuck.). 



Longmire Springs, Washington, Coll. E. T. Harper, 1906, and Olympic 

 Mountains, Washington, Coll. T. C. Frye, 1907, rocks. 

 Placodium aurantiacuin (Lightf.) Naeg. & Hepp. 



Islands of Puget Sound, 1906, rocks and wood. 

 Placodium cinnabarinum (Ach.) Anzi. 



Islands of Puget Sound, 1906, exposed rocks. 

 Placodium citrinum (Hoffm.) Leight. 



Jefferson County, Missouri, Coll. Colton Russell, 1899, shaded limestone. 

 Placodium ferrugineum (Huds.) Hepp. 



Brown Island in Puget Sound, 1906, bark. 

 Placodium galactophylhitn Tuck. 



Washington County, Missouri, Coll. Colton Russell, 1900, exposed lime- 

 stone. 



Placodium jungermanniae (Wahl.) Tuck. 



Near Laggan, Alberta, at 7,000 to 9,000 feet, 1906, among mosses. 

 Placodiiim lobulatum (Sommerf.) Fink. 



Waldron Island in Puget Sound, 1906, rocks. 

 Placodium miirorum (Hoffm.) Ach. 



Waldron Island in Puget Sound, 1906, rocks. 

 Placodium sideritis (Tuck.). 



Waldron Island in Puget Sound, 1906, rocks. 

 Placodium sinapispermum (Auct.) Hepp. 



Near Laggan, Alberta, 1906, rocks. Little known in North America. 

 Placodium ulmorum Fink. 



Near LaCrosse, Wisconsin, Coll. L. H. Pammel, 1892, and Rooks County, 

 Kansas, Coll. E. Bartholemew, 1893, bark. 

 Placodium vitellinum (Hoffm.) Hepp. 



Waldron Island in Puget Sound, and near Laggan, Alberta, 1906, soil and 

 rocks. 



Psora crenata (Tayl.). 



Laramie County, Colorado, at 7,000 feet. Coll. Mrs. C. F. Baker, 1895, 

 soil. 



