JOURNAL OF THE COLLEGE OF SCIENCE, TOKYO IMPERIAL UNIVEESITY. 



VOL. XLIV., ART. 7. 



On Some Fossil Shells from the Island of Saishu in 

 the Strait of Tsushima. 



By 



Matajiro YO KO YAM A, Rigakuhakushi. 

 Professor of Palaeontology, Imperial University of Tokyo. 



With 1 Plate. 



Several years ago, Prof. Shintaro Nakamiira of the Imperial 

 University of Kyoto, then a geologist of the Geological Survey of 

 Korea, sent me some fossil shells for examination, which he had 

 collected on Saishu, an island at the western entrance of the Tsu- 

 shima Strait, generally known under the name of Quelpart among 

 Westerners. 



The fossil locality is a sea-clifï near the hrook flowing at the 

 western end of Seikiho,* a small anchorage on the southern coast 

 of the island. According to a note attached to the fossils, the 

 rock-layers composing the cliff seem to be nearly horizontal and 

 three in number which, counted from below, are as follows: 



1. Sand. About 100 feet in thickness and containing some 

 argillaceous layers in the upper part and having two shell-layers, 

 one at about 50 feet, the other at about 60 feet above the level 

 of the sea. The lower layer is 3-6 feet thick and entombs Mol- 

 lusca, while the upper is somewhat less in thickness and rich in 

 Brachiopoda. 



2. Volcanic agglomerate. About 20 feet thick. 



3. Trachytic lava. About 60 feet thick and occupying the 

 highest part of the cliff. 



