o10 NATURAL SCIENCE [December 
paper, designates the mammals among them as distinctively ‘ Eastern 
or ‘ Siberian.’ The absence of these Siberian mammals from Ireland 
may perhaps be regarded as the central fact on which his views con- 
cerning the British fauna are founded. Most of the animals of this 
group die out in Great Britain as one travels north or west. It must 
be specially noted, however, that the mammals range over the greater 
part of the island. ~The Common Hare extends from Cornwall to 
the shores of the Pentland Firth ; the Weasel and the Viper range far 
north into Scotland. But most of the corresponding invertebrates. 
are not found north of the Trent or west of the Severn. 
The naturalist in Ireland is compensated for the loss of this 
eastern fauna by the presence of two most interesting and distinct 
sets of animals, almost unrepresented in the south-east of England. 
It has been mentioned that the Common Hare is absent from 
Ireland, but the Varying Hare (Lepus variabilis) occurs all over the 
country, from north to south, both on the hills and in the plain. 
This is a typically arctic and alpine animal, with a complete circum- 
polar range, confined in Great Britain to the Highlands of Scotland. 
Quite a number of insects, which in Great Britain are to be found 
only in the north range to the extreme south of Ireland, such as 
the marsh ringlet butterfly (Coenonympha typhon) and the ground- 
beetles Carabus clathratus and C. glabratus. But perhaps the most 
striking example of this northern fauna is the ground-beetle 
Pelophila borealis, which has been found in most of the northern 
and western counties of Ireland, from Antrim to Kerry in the far 
south-west. This beetle is, so far, unknown on the mainland of 
Great Britain, but it occurs in the Orkneys; on the continent it is 
an inhabitant of high northern latitudes. Together with this arctic 
and alpine group may be mentioned the three species of North 
American fresh-water sponges, phydatia cratervformis, Hetero- 
meyenia Ryderi, and Tubella pennsylvanica, which Dr Hanitsch? has 
lately described from lakes in western Ireland. These are com- 
parable to the few North American plants which grow wild in the 
same districts. One or two of the plants have Scotch stations; but 
both plants and sponges are unknown on the continent of Europe. 
The second characteristic group of the Irish fauna—hke the 
peculiar plants of the western counties, the Arbutus, London Pride, 
and St Dabeoc’s Heath—shows striking affinity with the life of 
south-western Europe and the Mediterranean region. Forbes, in 
his memoir already referred to, expressed the opinion that no fauna 
corresponding to this Hibernian flora exists in the British Isles. 
Everyone, however, agreed in assigning to this type the Portuguese 
slug, Geomalacus maculosus, when it was discovered spread over a 
small area in counties Cork and Kerry. Recently a number of 
1 Trish Not., vol. iv., 1895, pp. 122-1381. 
