7 CUMMINGS 



In addition to the stations mentioned above, it was collected by Dr. 

 Hayes at Prince William Sound and by Dr. Bean at Port Clarence, 

 Alaska, and at Plover Bay, Siberia. 



On bark and dead wood. Associated with species of Physcia, Le- 

 canora, Placodium, and Pyrenula. 



23. Buellia parasema triphragmia (Nyl.) Th. Fr. 



Lecidea triphragmia NYLANDER, Prod. 141. 1857. 



Buellia parasema triphragmia TH. FRIES, Lich. Scand. 590. 1871. 



Orca, 1150 feet (Trelease, 813) , St. Michael (Setchell). New to 

 Alaska. 



On Alnus. The thallus is exceptionally smooth and not limited by 

 the hypothallus. An examination of numerous specimens shows that 

 the thallus is usually smoother when growing on the bark of living 

 trees than it is on decaying trees or on the earth. 



Widely distributed ; may occur anywhere. 



In addition to the species named above, Rothrock records the follow- 

 ing species as having been collected by Dr. Bean : B '. albo-atra 

 (Hoffm. Nyl.) Th. Fr., at Unalaska ; B. atro-alba Fr., on St. Paul 

 Island and Unalaska Island and at Plover Bay, Siberia ; B. atro-alba 

 chlorospora Nyl., on Chamisso Island in the Arctic Ocean. The 

 two latter species are given by Tuckerman as synonyms of B. col- 

 ludeus (Nyl.) Tuck. J. M. Ma conn collected B. alpicola (Nyl.) 

 Anz. at St. George Island, also a Bttellia, species undetermined. 

 Tuckerman records the occurrence of B. parmeliarum (Smrft.) Tuck., 

 parasitic on Cetraria fahlunensis, collected by Wright on islands in 



Bering Strait. 



LECIDEA. 



KEY TO THE SPECIES. 



Thallus interspersed with reddish tubercles panceola. 



Thallus not interspersed with reddish tubercles. 



Apothecia innate tessellata . 



Apothecia superficial, or if innate, becoming emergent. 

 Apothecia innate, becoming emergent. 



Thallus yellowish- white, apothecia medium size contigua. 



Thallus grayish, apothecia very small nigrocinerea. 



Apothecia always superficial. 

 Thallus smooth. 

 Thallus thick. 



Thallus glaucescent alboccerulescens. 



Thallus orange-red alboccerulescens jlavoccerulescens. 



