144 MISSOURI BOTANICAL GARDEN. 
Lichenes Boreali-Americani, Cummings, Williams, Seymour, 1894- 
9. 
Decades North American Lichens, Cummings, 1899-1903. 
Lichenes Exsiccati, Mr. G. K. Merrill, 1909— 
3 Lichenes Nova Angliw, Howe, 1909-10. 
Kryptogame Exsiccati, Dr. A. Zahlbruckner, 1894— 
Lichenes Rariores Exsiccati, Dr. A. Zahlbruckner, 1902-04. 
Lichenes Rariores Veneti, Anzi, 1863. 
f Lichenes Etrurie Rariores Exsiccati, Anzi, 1863. 
| Lichenes Sueci# Exsiccati, E. Fries, 1818-1827. 
Lichenes Americe septentrionalis Exsiccati, Tuckerman, 1847-1854. 
. Mexican Lichens, Pringle, 18— 
Lichens of Eastern North America, Small, 189— 
; Lichenes arctici collecti «state, Fellman, 1863. 
| Herbarium Lichenum Fenniz, Norrlin et Nylander, 1875-1882. 
Lichenes Scandinavie Exsiccati, Th. Fries, 1859-1865. 
Die Flechten Europas, Hepp, 1853-1867. 
Lichenes Helvetici Exsiccati, Schaerer, 1823-1852. 
Lichenes Europxi Exsiccati, Rabenhorst, 1855-1879. 
Lichenes Suecie Exsiceati, Stenhammar, 1860-1865. 
Lichens de la Normandie, Malbranche, 1863-1869. 
Lichenes Flore Rossie, Elenkin, 1906-1907. 
Lichenes Exsiccati circa Cantabrigiam, Larbalestier, 1896. 
Division: Thallophytes. 
Suppivision: Lichenes (Tournefort) Micheli. 
Cuass: Ascolichenes A. Zahlb. 
Lichens in which the spores are enclosed in asci. 
Susciass: Lichenacee Nyl. 
Thallus nongelatinous, gonidia heteromerous. 
OrpER: Gymnocarpales (Luyken) Fr. 
Apothecia open, epithecium visible. 
Suporper: Cyclocarpinex Wain. 
Apothecia discoid; spores maturing in the asci: no 
capillitium. 
Group: Radiate Hue. 
Thalline structure radially symmetrical ; thallus attached 
to the substratum without rhizoids. 
