THE NATURAL HISTORY OF DONEGAL. 149 
retired to the south as the glacial period set in, again returned to 
their former haunts, whilst not a few became extinct. 
Finally, Period 1V.—After an interval, more or less lengthened, 
the ultimate separation of the British Islands from the European 
Continent, and of Ireland from England took place, resulting in 
the geographical outline now delineated in a map of Europe. 
Unreckoned ages are included in these changes, and no one can 
form even an approximate idea, according to modern computation, 
of their extent or duration. 
THE NATURAL HISTORY OF DONEGAL. 
[At a meeting of the Glasgow Natural History Society, held on the 30th 
January last, the following paper, entitled “ Notes on the Natural History 
of County Donegal, with some Account of its Archeology,” by Mr. James 
A. Mahony, Corresponding Member, was read. ‘The paper was illustrated 
by an enlarged map of County Donegal, and was accompanied by lists of 
the phanerogamous plants and ferns, and of the birds of the district.] 
A GLANCE at a map of Donegal will show that it is a county of 
considerable extent, generally very hilly, and with a coast line of 
most irregular character. Lough Swilly, Mulroy Bay, and Sheep- 
haven are arms of the sea penetrating southward from the Atlantic 
from twelve to sixteen miles, and modifying the climate so much 
that when snow falls, as it does very rarely, it never lies, but dis- 
appears in a very short time. These deep-sea fiords, with their 
rich marine fauna and flora, the coast outside beaten by the Atlantic 
surge, the numerous fresh-water loughs—many of them of con- 
siderable size—the bogs, mountains, marshes, sands, and cultivated 
grounds, present such a variety of conditions as is most favourable 
to the student of Natural History. I propose briefly giving some 
account of the Geology, Botany, Zoology, and Archeology of the 
district. 
The primary and metamorphic rocks form the backbone of the 
County Donegal. In very local patches, and in small quantities, 
the more valuable minerals and metals occur. Lead, copper, silver 
and gold have been found, but so sparingly as would not repay the 
expense of working. The post-tertiary deposits are everywhere 
met with, and are often full of interest. The boulder clay is very 
