igiS. Praegar. — Irish Fossil Mollusks. 71 



The first two groups are mostly of recent date and of little 

 palaeontological importance. The third, from its nature, 

 cannot yield much non-marine material. It is to the fourth 

 and sixth especially that we must look for evidence of value, 

 since the cave deposits are often difficult to zone owing to 

 disturbance by burrowing animals. Old land surfaces are 

 most important, but those hitherto examined have been 

 mostly in sand-dunes, where there is great risk of derived 

 material. 



Following on the descriptions of sections and lists of their 

 moUuscan contents, our authors devote 25 pages to " Notes 

 on some of the moUuscan (ienera and Species." There is 

 much valuable critical matter here, but Irish conchologists 

 will not agree with some of the conclusions reached, and some 

 of the statements made are misleading — for instance, 

 " Tnincatellina minutissima (Hart.) is said to occur in 

 Ireland from a single specimen (since lost) from North 

 Kerry," the fact being, as I am informed by Dr. Scharff, 

 that two specimens collected by J. R. Hardy at Killarney 

 are in the Dublin Museum. The authors have in this 

 section occasionally " let themselves go " on points which 

 have no reference to the proper subject of the paper, e.g., 

 the criticism of Mr. Taylor in connection with Vitrina 

 pyrenaica on pp. 159-161. 



The final section of the paper — " The Origin of the Irish 

 Non-marine MoUuscan Fauna " — is very interesting, and 

 also the most debatable, but I am not qualified to discuss 

 it, from the point of view of the Mollusca. The authors 

 recapitulate three theories, which they aptly name the 

 Edward Forbes theory (with which readers of this Journal are 

 well acquainted), the Pan-Germanic theory (" recently 

 advocated by J. W. Taylor, that our non-marine moUuscan 

 fauna originated in Germany . . ."), and the Glacial 

 extermination theory, as ably advocated by Clement Reid in 

 these pages (vol. xx., p. 203 et seq.). They discuss all three, 

 pointing out that the first was founded on a stud}^ of the 

 fauna and flora both fossil and recent, the second on a con- 

 sideration of the living non-marine mollusca, and the third 

 on palaeobotanical and geological evidence. As regards the 

 second, our authors unhesitatingly reject it on the grounds 



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