Fossils from the M iura Peninsula and its Immediate North. 21 



7. Terebratetta ptdvinata Gould. Habitat: Puget Sound in 

 Washington. 



If we add those 7 to the above, the total number of l'omis not 

 yet known as living either in the whole world or in the Japanese 

 waters becomes 95 which is about 40% of the whole fauna. 

 Naturally, there is a great possibility of future discoveries reducing 

 these numbers. But as the Japanese Molluscan fauna is already 

 pretty well known, a great reduction in them is hardly to be 

 expected. I think, the above percentage will not fall far below 

 one-third of the whole fauna, in which case the fauna is to be 

 ascribed to the Pliocene, and not to its upper-most part but some- 

 what lower, somewhere near the Red Crag of Newbourne, Eng- 

 land (Newbournian) which is considered as an equivalent of the 

 Amstelien of the Netherlands. 



A comparison of the Japanese fossil fauna with that of foreign 

 countries is at present of little value, as the species in common are 

 remarkably few. They are only the following: 



1. Volvula acuminata (Drug.). — Pliocene of Europe. 



'1. Admete viridula (Fabr.). — Pliocene of Europe. 



.">. Mitra chenus Lam. — Miocene and Pliocene of Europe. 



4. Mitra fusiformis (Broc). — Miocene and Pliocene of 

 Europe. 



Ö. Triton oregonensis Redf. — Pleistocene of California. 



6. Macoma inquinata Desh. — Pliocene of California. 



7. Venerupis irus L. — Pliocene of Europe. 



8. Lucina borealls L. — Pliocene and Pleistocene of Europe. 

 '.). Mod tola modiolus L. — Pliocene of Europe. 



10. Lima subaur'tculata Mont. — Miocene and Pliocene of 

 Europe. 



11. Pectcu tigerrinus Müll. — Pliocene of Europe. 



12. Terebratulina caput -serpent is L. — Miocene and Pliocene 

 of Europe. 



And if Natica clausa, Prod, et Sow. be really identical with 

 Natica janthostoma Desh. as asserted by some, then as the former 

 is found in the Pliocene and Pleistocene of California and the 



