450 THE AMERICAN NA TUBALIST [Vol. LVI 



and in the region of the Yenisei Eiver in Siberia. Ac- 

 cording to the author, in the Transbaikal region the 

 same species occurs in association with the giant woolly 

 rhinoceros {Diceros antiquitatis), with the hairy mam- 

 moth {Eleplias primigenius), and with the heavy-horned 

 bison {Bison crassicornis) . 



Quite a different order of distribution has the remark- 

 able Desmostylus, a sirenian or sea cow peculiar to the 

 coasts of the Pacific Ocean, first described from the Cali- 

 fornia coast many years ago by Professor Marsh and 

 more recently recorded from Japan. The Japanese 

 species is much more specialized and of larger size than 

 the forms occurring on the Oregon and California coasts^ 

 which points to a general migration from east to west, 

 that is, from the Orient to the Pacific coast of North 

 America. 



From this series of papers we are able to draw up the 

 following table showing the principal distribution of the 

 species of mammals in the descending order of the de- 

 posits in Japan: 



Postpliocene of Shozu-shima (Sanuki) : Stegodon sinen- 

 sis, S. orientalis, Loxodon antiquus namadicus, Bi- 

 son occidentalis, Cervus {Silia) cf. nippon. 



Upper Pliocene of Ikadachi-mura (Omi): Stegodon si- 

 nensis, S. orientalis, Buffelus sp. 



Middle Pliocene of Tomuro (Kaga) : Elephas aurora. 



Upper Miocene of Kuji (Hitachi) : Stegodon cf. latidens. 



Middle Miocene of the Provinces of Teshio, etc.: Des- 

 mostylus japonicus. 



Lower Miocene of the Province of Mino: TrilopJwdon 

 cf. angusiidens, Teleoceras sp., Amphitragulus wiino- 



The present researches of Doctor Matsumoto on the 

 rich Fayum collections of the American and British 

 Museums have enabled him to draw an important dis- 

 tinction in northern Africa between the true forest-liv- 

 ing mastodons, which appear to be directly descended 



