1 6 Proceedings of the Roi/al Irish Academ//. 



is furnished by the iuvertebrates. Our special attention is drawn by Mv. Born 

 to the importance of the " Iluuniug Beetles " of the genus Carabus. From 

 tlie fact of their being wingless and usually found under stones or clods 

 of earth, they are not liable to be transported accidentally by any of 

 the means usually supposed to aid animals in their dispersal. Mr. Born 

 claims that at least two European species of Carabus, viz. C. catenvlatus and 

 C. lumwralis, have crossed the Atlantic by means of an ancient land-bridge. 

 A third form — Carabus i/nvnlandicus Chant isson is — seems to ha^•e originated 

 in America, and to have travelled from there to Greenland and Lapland.' 



Of another group of insects — tlie Collembola — Prof. Carpenter remarks : 

 "It is of interest to find that the presence of not a few species of these 

 wingless insects in America, in Greenland, in the islands to the north of 

 Europe and Asia, and on the Euro-Asiatic continent, lends support to our 

 belief in a I'lioceue or I'leistocene land-connexion to the north of the Atlantic 

 Ocean — a lielief already upheld by so much evidence, both geological and 

 zoological."' 



The buttertiies and moths do not yield mucii evidence in favour of the 

 view of a North Atlantic land-connexion. Yet Mr. Petersen cited no 

 less than twelve species as occurring in arctic Europe and arctic America, 

 while absent from Asia, He thought that this fact pointed to the possibility 

 of a direct laniUbridge between the two continents.' At least three kinds 

 of butterflies are known to breed in Greenland, and to go through their 

 complex life-history within the confines of tiiat inhospitable country. 



Quite a number of naturalists lielieve that any resemblance between the 

 European and the American fauna must have arisen, not from any direct 

 intercourse iMjtween Europe and America, but by a migration across Asia 

 and a Bering Strait land-connexion. Tlie supposition of an ancient nortiiern 

 Pacific land-bridge presents fewer difficulties to them than the Atlantic one, 

 and is preferred for that reason. Dr. Ilorvath, for example, who states that 

 no less than 128 species of Hemiptera are common to the two continents, 

 argues that they all must have crossed Asia in reaching the one from the 

 other.* 



But Dr. Horviith and those who t^ree with him were apparently unaware 

 that certain freshwater species common to Europe and America are almost 

 totally absent from Asia or western America. 



Let us take, for example, our common Perch {Perm Jlnvialilis), a variety 



' Bom, Paul, " Carabologij'cbe Studicn," pp. 8, 9. 

 ' Carpenter, G. fl., " Cullembola from Franz Joseph Ijind," p. 276. 

 ' Petersen, W., " Lepidopterenfauna der arktiscben Gebiete," p. 38. 

 * Horrlitb, G., " Faunes b^mipterologiqucs," pp. 4-7. 



