Howe: LICHENS COLLECTED IN THE YUKON REGION 293 
No. 82, an Acarospora ‘‘no spores.’’—Hasse. 
No. 49, a Lecidea, probably belonging to the L. arctica Sommf. 
group of the L. alpestris stock, ‘differing from that probably in 
the brown color of the thallus granules.’’—Riddle. 
I have followed the order and classification of Miss C. E. 
Cummings’ Lichens of Alaska for convenience of comparison. 
The species numbered in black faced type were not included in 
the body of that work, though sometimes listed under “Ad- 
ditional Species.’ 
THOREAU MUSEUM OF NATURAL HISTORY, 
ConcorpD, Mass. 
