TRANSACTION'S OF THE SECTIONS. 157 



species of butterflies, the numbers being ninety-six and eighty-nine ; and the neigh- 

 bourhood of Berlin is, as any traveller can testify, very monotonous, and not 

 particularly likely to yield any extra variety of forms. 



In the same way we find that there are fewer species of butterflies in the western 

 counties of England than in the eastern counties. 



Dr. Speyer has suggested that the more continental character of the climate of 

 Eastern Germany, the greater cold in winter, and greater heat in summer, was favour- 

 able to the development of butterfly-life, and tended therefore to account for the 

 greater number of species there. This theory is certainly corroborated by the distri- 

 bution of the species with us : their maximum is reached in those portions of 

 England which have the most continental climate. 



In respect of the species peculiar to moors and mountains, it is needful to bear 

 in mind that it is not latitude that effects their distribution, but the position of 

 mountain chains of sufficient elevation. Thus the London entomologist travels 

 north to obtain species which an entomologist at Brussels would seek in the south ; 

 and even in Ireland an entomologist would need to go southwards to obtain species 

 in Kerry, which an Edinburgh entomologist would seek in the Highlands. Though 

 Ccenonymplia Davus is unknown in Southern England, simply because we have no 

 boggy mosses there, yet in Bavaria we meet with mosses similar to Chat Moss near 

 Manchester, and there this insect is again abundant. 



From a comparison of the species which occur in Ireland with those found in 

 Scotland, it appears that all the twenty-five, generally common species, occur in 

 Scotland, though three, Argynnis Silene and Euphrosyne, and Thymele Alveolus, have 

 not yet been detected in Ireland ; of the more southern forms, fourteen occur in 

 Ireland, but only five in Scotland ; on the other hand, one of the mountain species 

 common in Scotland, Erebia Blandina, has not yet been found in Ireland ; and one 

 straggler, Vanessa Antiopa, has occurred in Scotland, but not in Ireland. 



In short, six species occur in Scotland but not in Ireland ; on the other hand, 

 eleven in Ireland, but not in Scotland. 



Of the twenty-five more southern species, one, Vanessa Io, attains the latitude of 

 Edinburgh on the eastern side of our island, and occurs right across the country, 

 having been found at Falkirk and Renfrew. Of the remaining twenty-four, seven 

 stop short at Darlington, nine at York, and eight at Peterborough ; — that is, these 

 are, speaking roundly, their northern limits on the eastern side of the island ; several 

 of them travel further north on our western shores ; thus Colias Edusa, which is 

 unknown at Newcastle-on-Tyne, has appeared in Dumfriesshire, in Ayrshire, and in 

 the Isle of Arran. Argynnis Paphia, which has not actually occurred quite as far 

 north as Darlington, has been observed at Arrochar, and even in the neighbourhood 

 of Rannoch. 



Of the three moor and mountain species, Ccenonymplia Davus is that which is 

 found furthest south in England ; it occurs near Uttoxeter, and is plentiful on the 

 mosses between Warrington and Manchester ; it also occurs at Thorne Moor in 

 Yorkshire, and on wet bogs near Newcastle and near Carlisle. In Scotland it is 

 very general on mosses and hill-tops. In Ireland it occurs in the counties of Cork 

 and Kerry. 



Erebia Blandina is first found at Wharfdale in Yorkshire, then at Colne, Kendal, 

 and at Castle Eden Dene. In Arran, Argyleshire, Dumbartonshire, Perthshire, &c, 

 it is widely distributed. 



Erebia Cassiope is not found further south than Langdale Pikes and Styehead 

 Tarn ; it always occurs at a great elevation, from 1500 to 2000 feet above the level 

 of the sea. In Scotland it occurs on Ben Lomond and on some of the Perthshire 

 mountains. In Ireland it occurs at Galwayand Donegal. 



With regard to those species which are excessively local with us, the circumstances 

 which cause their restriction to such very confined localities are at present unknown 

 to us. They are not so restricted on the continent ; Pupilio Machaon and Polyom- 

 matus Acis are universally distributed in Germany ; and with the exception of 

 Pamphila Actceon, all our other local species are very generally distributed in 

 Germany, though not occurring in every district. 



Of the three stragglers in this country, Pieris Daplidice, Argynnis Lathonia, and 

 Vanessa Antiopa, the two former seem confined to the southern counties of England, 



