-67- 



tions given for species in the present paper refer to plants collected in North 

 America only. 



The following herbaria have been examined in the preparation of this work: 

 SuUivant Moss Chapter, Prof. Bruce Fink's, Carnegie Museum, Wellesley 

 College, Academy Natural Science, Dr. L. W. Riddle's, Dr. A. C. Herre's, Dr. 

 H. E. Hasse's, Boston Society of Natural History, Sprague, Taylor, British 

 Museum, New York Botanic Garden and Kew (in part). Museum d'histoire 

 naturelle, Cosson, U.S. National, Victoria Memorial, and the Author's. 



Section: Ellipsosporae R. H. Howe, Jr., Class. Fam. Usneaceae, 1. c. 17, 



1912. 



Asci containing 8 hyaline, ellipsoid or oblong spores "^7^ /*• 



3 '5 75 



Series: Desmazierae (Mont.) Ann. Sci. Nat. 18:303. 1852. {Corticatae 

 Stnr. Oesterr. Bot. Zeitsch. 54: 351. 1904.) 

 Axis with more or less chondroid, coalescent hyphae, cortex thin (50-60/i) 

 hyphae not divaricate above gonidia. Spermogones dark. 



The plants of this Series show an enormous variation, due to age and char- 

 acter of substrata. Only two distinct types are, however, evident — the two- 

 edged and the subterete. Of these there are those modified by a somewhat 

 constant apothecial position either lateral or terminal and further modifications 

 are seemingly only of growth. The spores of all the species are inseparable. 



Key to the Series {Desinazierce)* 



Thallus rigid 



Laciniae terete or subterete 

 Apothecia mostly lateral 



Branches stout (2 mm. diam.) 



Esoraliate ceruchis 



Soraliate f. cephalota 



Branches slender (i mm. diam.) v. tumidula [humilis] 



Apothecia terminal, corymbose comheoides 



Branches stout (4 mm. diam.) v. rohusta 



Laciniae subcompressed, angulate or com- 

 pressed (2-edged) 

 Apothecia lateral 



Thalline exciple rugose homalea 



Thalline exciple smooth v. disrupta 



Apothecia terminal, aggregate 



Branches wide (8-10 mm.) tesiudinaria 



Branches narrow angulate, lacunose. . v. intermedia 

 Thallus lax flaccescens 



All specimens show a more or less pale yellow reaction to KOH and hy- 

 menium blue with 1. Those on mineral substrata show the most pronounced 

 yellow with KOH. 



* A general key of all species will be given at the end of this paper. 



