yjQ Art. 1. — M. Yokoyama : 



Surface with radiately divergent striae, the divergent character 

 being most conspicuous on the anterior as well as on the posterior 

 slope; striae fine, tolerably dense, with an interstitial one towards 

 the ventral margin and cut by fine concentric lines of growth, 

 wdiereby they become more or less crenulate, thougli not always 

 distinct. Inner margin of shell crenulate all around. Beaks 

 small, though somewhat inflated. 



One ot the left valves measures about 2 milhm. in length, 2.5 

 millim. in height and 1 millim. in depth. 



A. Adams described several species of Crenella from the Japan 

 Sea in the " Annals and Magazines of Natural History " of 1862, 

 witliout giving any figure. But none agrees exactl.y with the 

 present one, though it seems to be closely allied to what he called 

 Crenella spectabilis. 



Compared with Crenella decussata Mont. (Forbes and Hanley, 

 British Moll., IV, pi. 45, fig. 2) which lives in the Corea Strait, 

 the fossil form has tlie cardinal margin more rounded and the 

 beaks less pointed, approaching in these respects Crenella elegans 

 Desh. of the Paris Basin (Descrip. Anim. sans Vert., Atlas, pi. 76^ 

 figs. 6-9) in which, liowever, the rounded nature of the cardinal 

 margin is still greater. 



Fossil occurrence. — Shito (not rare). Ôji. 



Living. — Central Japan. 



Family Anomüdse. 



Genus ANOItllA, Linné. 

 386. A.nontia nippotiettsis, Yokoyama. 

 Anomia nipponensis. Yokoyama, Foss. Miura Peniii., p. 146, pi. XI, figs. 18, 19. 



This species still living in Japan has already been described 

 in my work above cited. It is much like Anomia laqueata Reeve, 

 though more equilateral and generally provided with more 

 prominent radiating wrinkles which, however, are almost 

 obsolete in some specimens. The colour of the living shell is dull 



