1907] HERRE—ILICHEN DISTRIBUTION 273 
descend to 20° F. or thereabouts, accompanied by more or less 
snow. ‘These conditions of course can be met only by lichens spe- 
cially adapted for such a life, of marked xerophytic structure, and 
there is no such enormous thalline development as is observed in the 
foothills or redwood formation. The lichen flora of this region, 
however, is not below that of any of the others in either number of 
species or of individuals. Important lichens of this region are: 
Collema plicatile Ach.; Gyrophora diabolica A. Zahlbr.; G. phaea (Tuck.) 
Herre; G. polyphylla (L.) Turn. & Borr.; Lecanora muralis diffracta Fr.; 
L. calcarea (L.) Sommerf.; L. sordida (Pers.) Th. Fr.; L. upsaliensis Nyl.; 
Lecidea caeruleo-nigricans (Lightf.) Schaer.; L. auriculata Th. Fr.; L. poly- 
carpa Fr.; Rhizocarpon geographicum DC.; Parmelia conspurcata (Schaer.) 
Wainio; Verrucaria terebrata (Mudd). 
The lists published are merely some of the most conspicuous of 
each area and are by no means exhaustive. In the author’s herbarium 
are more than 200 named species and sub-species of lichens which 
he has collected in the Santa Cruz region, with perhaps nearly a 
hundred more as yet unstudied or not satisfactorily determined. It 
is believed that the lichen flora of the region under discussion will be 
found to include more than 300 species and sub-species. 
SAN JosE£, CALIFORNIA 
