SciiARi-'K — S<»)ic Jlen/r/r/.s an the. AtlfoifiH Problem. 28o 



originated from tlio lu'Oaking up of a land wliicli was once more oi' less 

 contin'.ious, and wliiehhad been intercolonized along ridges and tracts 

 (now lost between tbc ocean), thns bringing into comparatively 

 intimate connection many of its parts ; whilst others were separated 

 by cbannels which served practically to keep them very decidedly 

 asunder (B, p. 564). 



It is of importance to note that a good many species of hiud- 

 mollusca from the Tertiary deposits of western Enropc have their 

 nearest living relations on the Atlantic Islands. Thus the opcrculate 

 genus Craqjedopoma is quite peculiar to these islands at the present 

 time ; but, ou the Continent, it first turns up in the Lower Eocene of 

 the Paris basin, then again in the Oligocene of the Isle of "Wight, and in 

 the Lower Miocene of Hochheim, and finally disappears in the French 

 riiocene strata. 



The peculiar Clausilise of the Atlantic Islands gioupcd in the 

 sub-genus BoettgeriahaxQ many features in common with the Miocene 

 group Laminifera, which has still a solitary living continental 

 representative in the Pyrenees. Many other Atlantic Island Mollusca, 

 especially among the Helicidte, have their nearest representatives 

 in the European Miocene. 



One of the most remarkable species of animals in these islands 

 is Phitonia ( Viqucs7ielia) atlantica, a subterranean slug-like Mollusc, 

 which, like Testacella, devours earthworms. It occurs on the islands 

 of Fayal and San Miguel under sphagnum and liverworts, and is 

 quite peculiar to the Azores. Professor Simroth, who first made 

 known to us its anatomaticiil structure, is of opinion that it has 

 originated on these islands (B, p. 223). Erom a similarity of the slug 

 fauna of southern Portugal, sorithern Spain, North Africa, and the 

 Canaries, the same author concludes that there was probably a broad 

 land-connection between these four countries, and that it must liave 

 persisted until comparatively recent times (B, p. 402). 



The influence of Wallace's views arc clearly traceable in Dr. 

 Kobfdt's earlier writings, in which he ridicules the idea of an 

 Atlantis and of a former iinion between the Atlantic Islands and 

 the Continent (A, p. 8). After having independently worked out the 

 same problem more recently, however, he came to precisely the 

 opposite conclusion. Comparing the European with the West Indian 

 and Central American faunas, he points out that the land- shells on 

 the two opposite sides of the Atlantic certainly imply an ancient 

 connection having subsisted between the Old World and the Xew, 

 which only became ruptured towards the close of the Miocene Epoch. 



