8 NATURAL HISTORY SOCIETY OF DUBLIN. 



Chester. Two specimens, among those exhibited by Dr. Wright, were 

 taken some years since near Eureedpore, in India, by Mr. Dunlop, and 

 present no appreciable difference from those taken by the same gentle- 

 man a few weeks- ago at Howth ; thus giving a striking proof of the 

 little difference that will sometimes exist between specimens of the same 

 species from very different parts of the world. It does not, however, 

 always happen, nor would it be reasonable to expect it, that such a dif- 

 ference in habitat leaves the insect itself unaffected thereby ; and hence 

 we find sometimes that in specimens from different countries, the orange 

 colour becomes very much intensified, at times even reflecting a purple 

 hue, while again it becomes paler. But in all these varieties, which for the 

 sake of convenience have received specific names, we have virtually the 

 same Colias edusa; and in all of them the under surface of the wings 

 remains with essentially the same marking. Looking at the distribu- 

 tion of this species from this point of view, we find it on the American 

 Continent from below Baffin's Bay to Patagonia. Two varieties are 

 described in Richardson's " Fauna Boreali- Americana;" and Charles 

 Darwin, while off the northern coast of Patagonia, writes thus, in his 

 charming " Naturalist's Voyage :" — " One evening, when about ten 

 miles from the Bay of San Bias, vast numbers of butterflies, in bands 

 or flocks of countless myriads, extended as far as the eye could range. 

 Even by the aid of a telescope it was not possible to see a place free 

 from butterflies. The seamen cried out ' it was snowing butterflies;' 

 and such, in fact, was the appearance. More species than one were 

 present, but the main part belonged to a species very similar to the 

 common English Colias edusa, Colias pyrrothea. It occurs from the 

 west of Kerry, in Europe, to the extreme east of Asia. Bremer, in his 

 catalogue of Lepidoptera of the AmoorLand, records C. edusa, var. 

 aurora, as being found there, while the var. chrysothema appears to be 

 confined to Hungary and Styria. If we consider C. myrmidonia as but 

 another variety, in which the fore wings have grown a little longer— 

 conforming, as it were, to an African type, then we find this variety of 

 edusa in Spain, on the coast of Barbary, and as far as the Cape of Good 

 Hope — C. electra (Linn.) being a local variety of C.myrmidonia (Esp.). It 

 does not appear that this — thus almost cosmopolitan — species is found 

 in Australia or the South Pacific Islands. 



Dr. Wright trusted he might be pardoned for thus taking up the 

 time of the meeting in placing three new Irish localities on record for 

 this butterfly, and for calling the attention of the members to the ever- 

 interesting problem of the distribution of animal life ; but it was only 

 by thus studying the varied forms and varieties of a species that we 

 could ever arrive at a just estimation of what a species really was ; 

 and such a study had this peculiar fascination about it — that it enabled 

 us to see the struggle for existence, acting with natural selection, 

 tending towards the creation of, to say the least, new forms of animal 

 life. 



In conclusion, he might remark that this was a most remarkable 

 summer for all kinds of Lepidoptera. Vanessa atalanta and Cynthia 



