GENERAL CHARACTERS OF THE OMOBI MOUNDS. 



The Onioii Shell Mounds lie on the western side of the Imperial railway 

 between Yokohama and Tokio, at a distance of nearly six miles from Tokio. 

 They may be seen from the car windows jnst after leaving Omori Station in 

 going toward Tokio. 



The railway has indeed passed through a large portion of the mounds, as in 

 the field beyond the track the ground is strewn with the fragments of pot- 

 tery and the shells formerly composing the deposit. The length of the deposit 

 along the embankment is about eightynine meteis. Its depth in the thickest 

 part is four meters. Another exposure of considerable thickness is seen, back 

 from the track at a distance of ninetyfive, meters, but whether it is a continuation 

 of the first deposit I have not been able to determine. 



The fields to the south show that in their cultivation another deposit has been 

 removed. 



The mounds are nearly half a mile from the shores of the Bay of Yedo. 



As deposits of this nature are always made along the immediate shore, whether 

 the}' be upon the banks of a river, or on the coast, the occurrence of these deposits 

 inland may be looked upon as an evidence that the land has been elevated since 

 they were made. And when they occur inland, geological, aud often historical 

 evidences are not wauling to support this view r . 



The shell mounds along the Baltic are in many cases far removed from the 

 coast line. They also contain species of shells not found in the Baltic, in conse- 

 quence of the freshening of th» water resulting from the geological changes that 

 have taken place in that water basin. 



Along the eastern coast of the United States, the ocean has been encroaching 

 upon the land, aud shell mounds in Casco Bay, Maiue, are in process of being 

 washed away by the waves. 



liev. James Fowler, in the Smithsonian Report for lb70, comments lipon the 

 absence of these deposits along the New Brunswick coast, and offers this as one of 

 the evidences that the sea is encroaching upon the laud, and calls attention to the 

 fact that buildings which stood at some distance from the shore, fifty years ago, 

 have since been washed away. . 



Geological evidences show that marked changes have taken place in the shore 

 line of the Bay of Yedo. A portion of these changes are recorded historically 

 on ancient maps of Yedo. 



Shell mounds discovered by Mr. Kanda and Prof. Yatabe in the Botanical 

 Garden, and others discovered by Prof. Chaplin aud Mr. Ishikawa in Oji, show 

 a recedence of the waters of the Bay of Yedo of from five to seven miles. 



In every case these mounds are on ground slightlv elevated above the sin- 



