ATLANTIC SPECIES 1 
while the dry sun-exposed south and west sides have few. 
An instructive instance can be seen where our main 
watershed divides Argyllshire to the west and Perthshire 
to the east, at the part of the latter county where its 
eastern watershed lies nearest to the west coast. This is 
at Tyndrum and Ben Laoigh. The west or Argyllshire 
side is dry and sun-exposed, with little suitable ground for 
hepatics, while the east and north sides, both belonging 
to the watershed of the German Ocean, have abundance of 
hepatics, among which are the characteristic Atlantic species 
Leptocyphus cuneifolius, Mastigophora Woodsii, Scapania 
nimbosa,and Cololejeunea microscopica, which have not been 
found elsewhere on our eastern watershed, with the excep- 
tion of the Scapania, which has been found on one locality 
in Kast Inverness close to its western boundary. It is the 
proximity of the Atlantic, not the watershed, which is of 
consequence, provided that there is moisture and shelter 
for these species. It is only in places with such moisture 
and shelter that the low-ground species of the Atlantic 
type extend eastward from the west coast. ‘These condi- 
tions prevail a short distance over the western watershed 
in the Trossachs, and this is the most eastern point in the 
centre of Scotland where the hepatic flora is rather western 
than eastern. Owing to the configuration of Scotland, 
especially with its south coast being practically on the 
Atlantic, longitudinal lines for the whole of the country 
cannot be satisfactorily quoted. 
Those species of Atlantic hepatics which are confined to 
the mountains have in several cases a more extended 
distribution eastward. This is so principally with those 
which occur on moist rock ledges, some of which are found 
in the Aberdeenshire Grampians. The wet climate of the 
mountains approximates more to that of the west coast, and 
these species are able to withstand a considerable amount 
of cold. On the other hand, our only alpine Atlantic 
species confined to dry rocks, Gymnomitriwm crenulatwm, 
while it is a common plant on the west coast, becomes 
gradually rarer as it extends to the east, until it becomes 
exceedingly rare on the Aberdeen Grampians. There is 
very little sheltered ground on our north coast. None of 
the characteristic species of the west coast have been found 
