FOSSILS FROM THE ENVIRONS OF TOKYO. 51 



129. CARDIUM BKAUNSI Tok. 

 PL III. Figs. 11. 



Shell very large, nearly trigonal, ventricose, equivalve, pos- 

 teriorly closed ; anterior and posterior sides nearly equal in cur- 

 vature, ventral margin semicircular ; umbones median and promi- 

 nent; highly projecting radiating ribs, numbering twenty in a large 

 specimen of 82""" length ; each rib rippled with very fine trans- 

 verse ridges. Characterized b}^ having a trigonal shape and a small 

 number of ribs. Length 82"™, height 88""", and breadth ôO'""". 



Oji (rare). 



m. CARDILM TOKYOENSLS Tok. 

 PI. III. Figs. 12 a and a'. 



Shell ovate ; anterior side rounded, posterior subtruncated, 

 ventral, almost semilunar ; umbones prominent ; radial ribs forty 

 two in number, alternating with tolerably deep narrow grooves ; 

 ribs smooth, crenulated only at the posterior jiart ; cardinal 

 teeth two, lateral tooth one on each side. 



Length Height Breadth 



orvniTO f)1 mm -i Omm 



This species differs from C. burchardl Dkr. in having smooth 

 ribs, a rather rounded outline, and a wider dorsal part. It much 

 resembles C. unicolor Sow. from the Philippines, but the latter has 

 crenulated and more numerous ribs and a greater height (100 : 06). 



One living specimen of this species in the collection of 

 our College was found somewhere in Japan, but the locality is 

 not given. 



»Shinagawa (rare). 



