376 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. 



Trie 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 {Lqms 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 clatliratus and C. glabratus. But perhaps the most 

 striking example of this northern fauna is the ground-beetle 

 Pclophila 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, Ephydatia crateriformis, Hdero- 

 meycnia Byderi, and Tubella pennsylvanica, which Dr Hanitsch 1 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 — like 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 Irish Nat., vol. iv., 1895, pp. 122-131. 



