SOME TERTIARY FOSSILS FROM THE MIIKE COAL-FIELD. 3 



489 ,, Homolopsis japonicus. 



538 ,, G y cas Fujiiana. 



608 ,, Cardiia mandaica. 



610 ,, Cedroxylon sp. 



613 ,, Aturia ziezac. 



625 ,, Perna JVishiyamai 



650 ,, Crassatella fusca. 



842 ,, Veneincardia nipponica. 



As seen from above, Venericardia nipponica occurs in 

 several horizons from 280 to 842 feet. Cardita mandaica occurs 

 at 400 feet, 405 feet and 608 feet, and at 405, together with 

 Venericardia nippotiica. Crassatella fusca is known from two 

 horizons, at 358 and 650 feet in the first of which it is found 

 together with Venancardia nipponica. All the others were 

 obtained from different horizons. 



Respecting the geological age of the formation, it is very 

 difficult to speak with exactness. But that it belongs to the 

 Palœogene or anterior half of the Tertiary is beyond all doubt. 

 Venericardia nipponica, which ranges from nearly the top of 

 the formation down to its bottom, is a near relation of V. 

 pectuncularis Lam. of the French Palœocene. Pholadomya mar- 

 garitacea and Aturia ziezac are Palœocene to Pliocene, in the 

 Occident ; while Lamna cuspidaia is hitherto known to occur 

 only in the Oligocène. It is therefore highly probable that we 

 have here a rock-complex which corresponds to the Palœocene 

 and Eocene of Europe. 



The same formation seems to be developed in at least two 

 places on the island of Amakusa, namely, at Hangochi and 

 Sakasegawa. From the former we possess Crassatella fusca and a 

 new species of Lima as described in the appendix ; from the 



