104 CUMMINGS 



Apothecia medium size. 



Disk of apothecium shining brown. 



subfusca argentata. 

 Disk of apothecium pruinose ................... .pacifica. 



Thallus not smooth, dirty white or yellowish. 



Margin of apothecia reflexed .............. varia symmicta. 



Margin of apothecia not reflexed. 



Thallus of rounded, turgid warts ........... frustulosa. 



Thallus contiguous, chinky. 



Apothecia rather small, margin entire ..... subfusca. 



Apothecia medium size, margin flexuose and cren- 

 ate ............................... .subfusca allophana. 



Spores very large. 



Thallus chinky or plicate .................................. pallescens. 



Thallus not chinky, either tartareous, granulate, or nodulose. 

 Lobes of the thallus short ................................ tartarea. 



Lobes of the thallus elongated. 



Thallus finely divided ........................ tartarea frigida. 



Thallus coarsely divided .................. tartarea pterullna. 



94. Lecanora privigna revertens Tuck. 



Lecanora privigna revertens TUCKERMAN, Syn. N. A. L. i : 204. 1882. 



Kadiak (Trelease, 900 in part) . New to Alaska. 



With Buellia geographica, Lecanora varia intricata, and Per- 

 tusaria communis. This variety has been collected in California by 

 Bolander. 



95. Lecanora cinerea (L.) Smrft. 



Lichen cinereus LINNAEUS, Mant. 132. 1767. 



Lecanora cinerea SOMMERFELDT, Suppl. Lapp. 99. 1826. SOWERBY, Eng. 

 Bot. 



Summit of White Pass, 3000 ft. (Trelease, 951 in part); Kadiak 

 (Trelease, 945) ; Port Clarence (Trelease, 941). All on rock. Col- 

 lected by Dr. Bean at Port Clarence, Icy Cape, and Cape Lisburne. 



The specimen from White Pass, which is mixed with Buellia geo- 

 graphica, differs from themore common form, in that the thallus is 

 not continuous, but broken into areoles. The specimen from Port 

 Clarence has the apothecia urceolate, and sometimes white pruinose. 

 Interspersed in the thallus are reddish-gray, granulose warts. This 

 is a very variable and widely distributed species, which has been 

 classified under several generic names. Common in Greenland and 

 in alpine and arctic regions. 



