4G ■ . Art. 6.— M. Yokoyama: 



Fossil occurrence in foreign countries. — Pliocene of Belgium; 

 Pliocene of England (Tryon). 



Living. — Circumboreal; in Japan, in Aniwa Bay, Sakhalin. 



Family Volutidae. 



Genus Voluta, Linné. 



30. Voluta megaspira Sowerby. 



Pl. II. Fig. 18. 



Voluta megaspira. Sowerby, Tbesaur. Conch., vol. I, Voluta, p. 208, pl. 48, fig's. 31, 32. 

 Donker, Index Moll., p. 49. Lischke, Jap. Meeres Conch., II, p. 167, in, p. 43. Pilsb&y, 

 Cat. Mar. Moll. Jap., p. 24. 



Voluta lyTiformis. Küster in Conch. Cab. Martini u. Chemn., vol. V, pl. 2, Volutacea, p. 

 177, pl. 28, fig. 1. 



Numerous specimens, especially from Koshiba, agree very 

 well with our living forms and also with the one figured by 

 Küster from an unknown locality. The longitudinal ribs or 

 plications generally become obsolete in the body-whorl, at least in 

 its last part. Traces of transverse striations are visible in some 

 specimens, especially in the upper half of the whorls. The 

 columella folds vary in number, but at least two with the lower 

 stronger, but often an intermediate fold and also a weaker one 

 above the upper fold are developed. 



The largest specimen from Koshiba which lacks the lower 

 portion is 40 millim. in diameter, so that the height, if perfect, 

 would be about 120 millim. The number of whorls is seven and 

 a half. 



Fossil occurrence. — Miyata Zone (Iwaiguchi and Jinya-ato in 

 Kami-Miyata); Kamakura Zone (Kewaizaka in Kamakura); Kana- 

 zawa Zone (Nojima and Kanazawa); Koshiba Zone (Koshiba); 

 Naganuma Zone (Naganuma and Iijima). Upper Musashino of 

 Kazusa. 



Living. — Northern, Central and Western Japan. 



