Miscellaneous. 185 



united these two parts of the world. The Atlantic islands had already 

 risen towards the south coasts of this continent at the diluvian period. 

 That this country was at the bottom of the sea during the miocene 

 epoch, is shown by the fossil shells of Porto Santo and St. Vincent 

 in Madeira and those of the Azores ; but that it had emerged at the 

 diluvian period is proved by the terrestrial mollusca of Cani9al, and 

 the fossil plants of St. Jorge in Madeira*. 



The islands formed at this epoch would have received their vege- 

 tation from the Atlantis in the diluvian period, and consequently at 

 an epoch when this continent had entered upon a new phase of deve- 

 lopment. If we suppose, that then, by a subsequent depression of 

 the soil, the connexion with America was destroyed, and subsequently 

 that which existed with Europe, we shall obtain the elements for the 

 explanation of the existing flora of these islands. We there find the 

 remains of the flora of the ancient Atlantis, and in consequence many 

 types of the Tertiary flora are retained there whilst they have disap- 

 peared in Europe. These remains, with a certain number of other 

 species, form the peculiar plants of these isles, corresponding in part 

 with the American species because they have issued from the same 

 centre of formation. But it is with Europe that these islands have 

 the most species in common, probably because their connexion with 

 this continent lasted longer. 



At the diluvian period the flora of central Europe was displaced by 

 great changes of climate (extension of glaciers, &c.) ; and as by the 

 depression of the Atlantis the connexion with America was destroyed, 

 the new European vegetation could not extend on that side, but only 

 towards the east. It is thus that the characters of the new vegeta- 

 tion would be explained, particularly that of the lower countries, whilst 

 the Alps and the north have undergone less change. This also is 

 the reason of the great analogies which occur between the north of 

 Europe, Asia, and America. I arrive therefore at the same conclu- 

 sion with yourself as regards these latter countries, namely that the 

 alpine vegetation is certainly the most ancient in our country, and 

 that subsequently when the climate became warmer, after the glacial 

 epoch, it rose from the low countries to the mountains and Alps. — 

 Bibliotheque Univ. de Geneve^ April 1856, p. 327. 



Note on Clausilia plicatula and C. Mortilleti. 

 By J, GwYN Jeffreys, Esq. 



Mr. Benson, in the last Number of the * Annals ' (p. 1^)^ states 

 that I omitted Clausilia plicatula in my *' Notes on the Swiss Mol- 

 lusca," as well as two other so-called species of Clausilia ; all of 

 which he had found in Switzerland. My reason for omitting C. pli- 

 catula was explained in the preface to my '* Notes," in which I said 

 I was induced to think that a notice of "some hitherto unrecorded 

 localities " which occurred to me might be interesting, and that I 

 adopted Charpentier's Catalogue as my text-book. By referring to 

 that catalogue it will be seen that Charpentier mentions C. plicatula 



* See Heer, " Ueber die fossilen Pflanzen von San Jorge in Madeira," 

 Zurich, 1866, 



