'X72 ^^'^- 1-— M. Yokoyama : 



Thracia ßhaseolina. Philippi, Euum. Moll. Sicil., I, p. 19, pi. I, fig. 7, II, p, 16. 

 Wood, Crag Moll., Biv., p. 260, pi. XXVI, fig. 2 abc. 



Two right valves and a Ijroken left. 



The shell is subquadrate, transverse, tliin, convex, with the 

 anterior side a little longer than the posterior, rounded in front 

 and truncate behind. The dorsal margin is onlv slight]}^ arched 

 and subparallel with the straight ventral. The surface has a 

 posterior carina which is distinct in spite of being rather bhnit. 

 T]ie sculpture consists merely of rough lines of growth. Palliai 

 sinus large, deep, rounded. 



The larger of the two right valves is 17.4 millim. long, 10.5 

 millim. high and 4 millim. deep. It looks quite like the specimen 

 figured by Wood in his Crag Mollusca above cited. 



Fossil occurrence in Japan. — ( )take, Kamenari. 



Fossil occurrence in Europe. — Pliocene of England, Belgium 

 and Italy; Miocene of Austria. 



Living. — Norway, British seas, ^lediterranean Sea. 



279. Thracia transtnontaiia, Yokoyama. 



PI. XIV. Figs. 13, 14. 



Shell small, thin, inequivalve Avith right valve convex and 

 left rather compressed, transversely elongated, subquadrate, inequi- 

 lateral with anterior side a little longer tjian posterior, rounded in 

 front, truncate behind. Antero-dorsal margin slightly excavated, 

 postero-dorsal straight, ventral ver}^ little arched. A distinct, 

 though not very sharp, posterior carina is present, behind which 

 the surface is somewhat depressed in the middle. The sculpture is 

 absent save lines of growth. Beaks small, pointed, bent back- 

 ward. Palliai sinus deep, rounded at end and reaching almost the 

 middle of the shell. 



Tlie following are the measurements. 



Length. Height. Depth. 



Left valve 9.9 millim. .5.0 millim. 1.1 millim. 



„ „ 8.4 „ 4.0 „ 1.0 „ 



Rio-ht „ 10.0 „ 5.4 „ '2.0 „ 



^' „ 8.1 „ 4.8 „ ' 1.3 „ 



