PREFACE. 



Tn the summer of 1879, 1 visited the province of Hitachi which is nearly 30 

 ri distant from Tokio, in order to collect molhisca in the lake of Kasumigaura. 

 Along the coast, there exist numerous fossil remains of marine shells which show 

 evidence that the lake had once been washed by the sea in past times. Bearing 

 in mind this feature, I carefully examined the southern coast of this lake for 

 shell heaps, and was finally rewarded by discovering three shell mounds on the 

 top of a hill known as Okadaira ; and afterwards found still other mounds at 

 several places not far from the. one previously mentioned, viz. one at Kihara, 

 two at Amimura, one at Shimadzu ; and on my return to Tokio, I again met 

 with a single enormously large mound at Kitakatamura in Shimosa. 



In the winter of the same year in company with Mr. Iijima I again visited 

 the same province in order to make still farther researches in regard to these 

 mounds by the order of Mr. Kato President of Tokio Daigaku. 



On this occasion, we found a number of other mounds in the same province 

 already mentioned before, but only one was completely examined, and that was 

 the Okadaira mound which was the largest and richest in ancient remains. 



The contents of this paper are mainly confined to the contents of this 

 mound, and one of our objects is to compare its features with those of the Omori 

 Shell mounds, which have been well described and accurately figured by Prof. 

 Edw. S. Morse in the first memoir of Tokio Daigaku. 



Our thanks are particularly due to the never failing advice of Prof. Edw. 

 S. Morse. 



Our thanks are also due to Mr. M. Nishi for the determination of the 

 nature of the stone implements and to Mr. H. Yoshida on chemical analysis, and 

 lastly we are much indebted to our two sincere friends Mr. 0. Taneda, and Mr. 

 M. Kikuchi for their kind assistance in many ways. 



To the artists Mr. J. Nomura, Mr. M. Indö, and Mr. K. Watanabe, our thanks 

 are specially due for the fidelity with which they have made the illustrations. 



I. IIJIMA. 



C. SASAKI. 

 Tokio Japan 



1st Sept. 2542 (18S2). 



