Climatic Changes in Japan siac9 Pliocene Epoch. 5 



38. Terehmtidina crosm Davidson. 



39. Terehratidina cailleti Crosse. 



I also found three forms which, if not quite identical with, 

 are at least close to, living species. They are 



40. Sipho cf. gracilis Da Costa. 



41. Natica cf. pallida Broderip et Sowerby. 



42. Fissuriaea cf. tanncri Verrill. 



The remaining twenty-nine species are those which are not 

 yet known to be living, and belong to the genera Conus, Pleurotoma, 

 Drillia, Mangilia, Mitra, Troplion, Bittium, Trichotropis, TurriteUa^ 

 Solarium, Acrilla, Scala, Dentaliwn, Diplodonta, Liicina, Astarte^ 

 Cardita, CrassateUa, Mijodora, Pcctcii, Östren, Neniodon, Terehratidina^ 

 etc. They amount to about 40% of the whole, and even when 

 reduced by future discoveries, can hardly be imagined as falling 

 below 20%. From this we may safely infer that the fauna can 

 not be younger than the Mildle Pliocene. 



But it is not this high percentage of extinct forms which has 

 struck me most. It is the decidedly boreal character of the 

 entire fauna. The following species are those which point to it: — 



1. Admete viridida. 



2. Chrijsodomus phœniceus. 



3. Chrysodomus pericocldion. 



4. Sijjho gracilis. 



5. Trophon clathratus. 



6. Priene oregoncnsis. 



7. Natica clausa. 



8. Natica pallida. 



9. Leptothyra amussitata. 



10. Puiicturella conica. 



1 1 . Corhula veniista. 



12. Pectcn yessocnsis. 



13. Pecten siüiftii. 



14. Leda ramsayi. 



15. Nucula insignis. 



Troplion clathratus and Admete mridula are well known circum- 

 boreal species. Chrysoloivis phoe:ilceus is now found on the coast 



