30 



Assuming length to be 100, night in ^ Jg jjJJJ^ y 8 * 5 



Length. Hight. 



„. . „ , . ' ( Eeeent, 95. 73. 



Dimensions of largest specimen | Mound> 106 - gl g 



Mya arenaria Liane. Plate xvin. Fig. 4. 



Not an abundant shell in the Mounds nor common along the coast. It is 

 often seen in the markets at Tokio, brought from Shinagawa. 



It will be seen by the figures that the proportions have changed slightly, 

 though the size remains nearly the same. 



Length. Hight. 



Average dimensions of f Recent, 98.5 62.1 



ten largest specimens, ( Mound, 98.2 -59.9 



Assuming length to be 100, hight in { l7 jßjjj^' 61 j 



Length. 



Hight. 



105. 



62.5 



112. 



60. 



Dimensions of largest specimen, !■»*-', i' 



The following species of Lamellibranchiates are present in the Deposits. 



Area subcrenata Lischke. 

 ,, iiiflata Reeve. 



,, {/ratios« Linne, 

 Dosinia Troscheli Lischke. 

 - Cyelina Chinensis Chemnitz. 

 Mactra reneri/ormis Deshayes. 

 My a arenaria Linne. 

 Cytherea meretrix Linne. 

 Tapes sp>. 



Solen stricht» Gould. 

 Lutraria NuttaUi Conrad. 

 Östren denslamellosa Lischke. 

 sp. 



Those species whose dimensions have been given were represented bj' a suffi- 

 ient number of specimens for the purposes of measurements and comparisons. 

 Of the others, with the exception of Östren, only a few specimens were found, 

 not enough to justify comparisons. 



It will be seen by the foregoing measurements that the following species from 

 the mounds are larger than their living representatives from the same locality : 



