Jgg Art. 6. — M. Yokohama 



centric ones. Lunula deep and ovate. Anterior lateral tooth 

 distinct. Inner side of the shell with fine radiating lines which 

 end at the palliai impression. Muscular scars distinct, the anterior 

 subfusiform and not much elongated, the posterior rather ovate in 

 outline. Inner margin finely crenulate. Length 8 millim., 

 height 7,5 millim., depth (of one valve) 2,~> millim. 



This species is very much like Lucina pisidlum above men- 

 tioned, but the radiating striae are decidedly finer, and not 

 divergent, 



Fossil occurrence. —Miyata Zone (Shimo Miyata). 



Family Chamidse. 



Genus Chama. Linné. 



171. Chama semipnrpurata, Lischke. 



Pl. X. Figs. 13, 14. 



Chama semipnrpurata. Lischke, Jap. Meeresconch., vol. II, p. 130, pl. VIII, fig. 1. 

 Pilsbrt, Cat. Mar. Moll. Jap., p. 134. 



The shell is thick and ovate; the free portion of the attached 

 or left valve is erect and high, with the anterior margin more or 

 less rounded; the right or free valve only a little convex, roundish 

 or oval. The sculpture consists of closely-set scales concentrically 

 arranged and assuming the form of half-open tubes and spines. 

 These scales are most developed on the free valve. Frequent. 



The examples are mostly small, the largest attached valve 

 measuring '25 millim. in height and 22 millim. in length. 



Fossil occurrence. — Miyata Zone (Kami-Miyata, and Okine); 

 Yokosuka Zone (Otsu). Upper Musashino of Shimosa and Kazusa. 



Living. — Central and Western Japan. 



Family Carditidae. 



Genus Card it a, Bruguieee. 



172. Cardita variegata, Bruguière. 



Pl. X. Fig. IG. 



Cardita var'egata. Bbuguièbe, Encycl. meth. vers., p. 407. Reeve, Conch. Icon., fig. 2. 

 Clessin in Syst. Conch. Cab. Mart. Chenm., vol. X, pt. 1. p. 23, pl. 3, figs. 8, 9, pl. XI, figs. 5, 6. 

 Pilsbrt, Cat. Mar, Moll. Jap., p. 135. 



