MOSSES. 47 
tains, they are common hyperborean mosses, 
growing most luxuriantly and spreading in wide 
patches on the rocky plains of Spitzbergen, and in 
the upland woods of northern Norway. <A few of 
them are found on the highest mountains of Wales 
and the south of Ireland; while the remaining 
representatives of these Alpine and Arctic mosses 
cover the projecting rocks which tower up through 
the glaciers of the Alps and the snows of the 
Pyrenees. No less than a dozen are exclusively 
restricted to the very highest summits of the most 
elevated peaks in Britain, never, except when 
brought down by streamlets in isolated tufts along 
their course, descending to a lower altitude than 
4000 feet ; while upwards of forty of the rarest 
species are found on Ben Lawers and the lofty 
hills in the neighbourhood, of which no less than 
twenty are to be found nowhere else in this 
country. On Ben Lawers alone 330 species occur. 
Some mosses are very much restricted in their 
range. The Glyphomitrion Daviesii—a minute 
darkish-green moss spreading over rocks generally 
near the sea—is peculiar, so far as known, to the 
British Isles, where it is exceedingly local, being 
found in one or two places in Ireland and Wales, 
and in Scotland on the trap rocks at Bowling on 
the Clyde. The lovely curve-stalked apple-moss 
(Bartramia arcuata), which covers moist banks 
