14 R. H. Howe: MANUAL OF THE GENUS USNEA 
branches rare or wanting ; fiérils equiform (5 mm. to 2 cm. long), 
stipate, rectangularly divergent, rarely dichotomous. <Afothecia 
(so far practically unknown in North American specimens) seen 
only in Bavarian examples, terminal on lateral fibrils, very small 
(max. diameter 3 mm.) subcyathiform, disk concolorous or buff, 
periphery ciliate.. Spores 7-10 % x 4-6 p. 
CONTINGENT PHASES: (@) Fibrils more or less sorediate. 
SussTRATA : Coniferous and deciduous trees, occasionally dead 
wood. 
GEOGRAPHICAL DISTRIBUTION : Common throughout the Boreal 
zone, reaching its highest development, like all the Usneas, on the 
Pacific coast. 
OsseERVATIONS: This plantis much reduced throughout our area, 
and has never been reported in fruit, except from the Santa Cruz 
peninsula, California (/7erre), where it is still inferior in develop- 
ment as compared with specimens from Bavaria. In the northern- 
most limit of its range, and in the east, it is distinctly virescent, 
whereas in the west and southwest it is stramineous. This charac- 
teristic color condition is true of all the filamentose Usneas in our 
area, ) 
The scarcity of North American material of the typically 
antarctic lichen Usnea sulphurea (Zoega) Th. Fr., reported only 
twice from the Arctic regions of North America (Melville Island, 
R. Brown, Babington ; and Greenland ; _/. Vah/), makes it impossi- 
ble to give to it the necessary study ; I am inclined, however, to 
agree with Nylander’s view, and place this dark-disked, at length 
interruptedly corded species in the genus Meuropogon of Nees and 
Flotow,* where it seems more naturally to belong,—set apart 
from the fale-disked, percurrently corded species here included 
under Usnea. The question of the ciliated apothecia, an unstable 
character, is not important. The spores here average distinctly 
larger. The species belongs to the papillate division. The genus 
Eumitria + of Stirton does not concern us in connection with our 
area. 
SYNONYMY 
The following list of titles is an attempt to give the original 
citations and type localities for all the described species of the 
* Linnaea, g: 496. 1835. 
tScot. Nat. 4: 100. 1881, 
