POSSn^ FROM THE ENVIRONS OF TOKYO. 77 



CohimhcUa scripta Lixxi';.; MangcUa striolata Phil.; Trichotropis coro- 

 nata (Jld.; Bulla cijlinâracca Pkxn.; Dentalium entalc Linnk.; Solcn 

 grandis Dkh.; Lasœa rubra INIont.; Pectunculus glijcimcris Linnk.; 

 Nueula cobbolcliœ Sow.; Limopsis aurita ]>küc.; Pectcn plica Linnk.; 

 Scalaria clathratula jNIont.; Scalaria eanecllata Bkoc. 



Looking at all the t^pecies described, it is quite certain tliat our 

 fossil beariuii' layers are deposits of a shallow sea. 



In settling the question wiiether our fossil Mollusca belong- 

 to a fauna, warmer or colder than the living, 117 species out of 

 165 are to be availed of, for the remainder are either extinct 

 or are such as are very rarely i'ound in a living state.''' Among 

 the 117 species I find the following 26 tropical ones : 



Rapana bezoar L.; Triton sauliœ L.; Hemifusus ternatanus ûmel.; Nassa 

 liveseens Phil.; Caneellaria spengleriana Desh.; Terebra alveolata 

 Hinds.; Pleurotoma oxijtropis Sow.; Pleurotoma gracilenta Rve.; 

 Dolium hiteostomum Kunster ; Sigaretus papilla Gmel.; Scalaria 

 immaeulata »Sow.; Scalaria lamellosa Lam.; Scalaria acuminata Sow.; 

 Turbonilla fusca A. Ad.; Pyramidella spirata A. Ad.; Cerithium 

 kochii Phil.; Potamides fluuiatilis Port, and Mich.; Potamides in- 

 eisus HiND.s and Jacq.; Turbo granulatus Gmel.; Troehus amussi- 

 tatus Old.; Troehus a'-gyrostomus Gmel.; Dentalium octogonum 

 Lamk.; Venus foliacea Phil.; Cytherea meretrix L.; Cardium muti- 

 cum Rve.; Area granosa L. 



And to the arctic species belong the following seventeen : 



Neptunea despecta Linné.; Buecinum undatum Linné.; Natica clausa 

 Desk.; Trichotropis vniearinata Brod.; Solen krausensternii Scii- 

 RENCK ; Panopœa generosa Gld.; Maetra saehalinensis Schrknck ; 

 Maetra suleataria Desii.; Tressus nuttali Conrad ; Tellina tenera 

 Say; Macoma nasuta Conrad; Venus stimpsoni Gld.; Cytherea 

 chinensis Chkm.; Tapes rigidus Gld.; Cardium californiense Di>h.; 

 Astarte japoniea Tok.; Yoldia lanceolata Sow. 



* It must be acknowledged tliat our three localities belong to the s:iuie fucies. The 

 reasons are explained later on. 



