Features of " Discina Acadica." 11 



stems of seaweeds. Similar differences of habitat may have 

 led to the characteristic form of the aperture and other 

 features which distinguish S. acadica from the more typical 

 Stenothecse. 



The vertical range of this species is not great, for it is 

 not known either above or below Div. lc, but it is rather 

 common where it does occur, and its associate species are 

 those that have been found to abound in comparatively 

 shallow water near the shore line. At an horizon corre- 

 sponding to that in which our species is found, occurs the 

 European Metoptoma barrandei (Linnarsson.) 



Fig. — Stenotheca (sub-gen. ?) acadica, Hartt, sp., magnified f , young 

 individual exhibiting the internal characters of the shell. The 

 horse-shoe shaped muscular impression open in front, the visceral 

 cavity with a sharp ridge thickening and stiffening the apex. The 

 inner area of the visceral cavity is lozenge-shaped opposite the 

 more rigid part of the dorsal ridge. 



Origin of the Ainos and theie Final Settle- 

 ment and Distribution in Japan. 



By D. P. Penhallow. 



The Ainos probably displaced an earlier race of people in 

 Japan, or at all events found remains of such a people there. 

 Considering, then, that they are not truly autocthonous, we 

 are led to inquire into their origin, as well as their first ap- 

 pearance in the country. Naturally, we first of all seek 

 evidence from the people themselves, concerning their an- 

 cestors and their first ajDpearance in the country ; but in so 

 doing we are furnished with traditional lore, which, however 

 interesting, often proves of little value in arriving at the 



