351 
Of the 25 lichens common to Eastern Nebraska and the Black 
Hills, 10 are found on rocks, 5 on earth and 4 on trees. Of the 
20 common to the Black Hills and Rocky Mountains, 11 grow on 
rocks, § on soil and but 3 on trees. 
The 83 species and varieties found in the Black Hills belong 
to 22 genera, the three largest being Lecanora with 16 representa- 
tives, Placodium with 10, and Cladonia with 7, though Lecidea, in 
the Tuckermanian sense, when well worked over will probably 
give nearly or quite as many species as Lecanora. The lichens of 
the Rocky Mountain list are distributed among 17 genera, the 
three largest being Lecanora with 17 species and varieties, Placo- 
dium with 10 and Lecidea with 8. 
Fourteen of the 17 genera are also found in the Black Hills 
and 13 in Eastern Nebraska, 12 of these being common to all 
three regions. The Nebraska list includes 31 genera. 
Turning now to the distribution given by Tuckerman* to the 
Species found in the Black Hills, and 45 are found to be general 
throughout the United States, 24 are Alpine or sub-Alpine, 6 are 
peculiar to the Pacific Coast, 3 to the Atlantic Coast, 3 to the 
great plains, and one a local form of a widely distributed species. 
One species, Rinodina mamilana, Tuckerm., has only been re- 
Ported from the Sandwich Islands and the Galapagos Islands. 
Again, 43 of the species have been reported from Arctic America, 
while but 26 have been found in the Southern States, and 10 of 
the 26 are found only in the mountains, leaving but 16 that can 
really be said to belong to the South, and these are all included 
in those species whose distribution is said to be general through- 
Out the United States. Sixty-two species are found in Europe, 
being either Alpine, sub-Alpine or confined to the North of 
of Europe. Seven species are peculiar to the United States. 
A comparison of the Black Hills list with Tuckerman’s 
Lichens of California, Oregon and the Rocky Mountains, shows 
that 24 of the species occur on the coast, while 30 are found in 
the Rocky Mountains, the 30 including nearly every one of the 
24 reported from the coast. From this list and the one by Mr. 
Willey it may be seen that in all 34 species of the Black Hills 
list have been found in the Rocky Mountains. 
* Synopsis North American Lichens, Parts I. and II. 
