Fossils from the Miura Peninsula and its Immediate North. 47 



Family Mitridae. 



Genus Mitra^ LAMARCK. 



31. Mitra ebenus, Lamarck. 



Pl. II. Fig. 4. 



Mitra ebenus. Lamarck, Annal, du Mus., vol. XVII, Xo. 58. Hist, Nat. VII, p. 319, No. 

 58. Sower: y, Thesaur. Conch., IV, Mitra p. 32, No. 428, pl. 368, figs. 329, 334-336. Tryon, 

 Man. Conch., IV, p. 121, pl. 36, figs. 84-88, pl. 37, figs. 89, 90. Philippi, Enuni. Moll. Sicil., 

 vol. I, p. 229, pl. XII, figs. 9, 10. Wood, Crag Moll., supplem., p. 7, pl. Ill, fig. 6. Hörnes, 

 Foss. Moll. Wiener Beckens, I, p. 109, pl. X, figs. 11-13. 



Mitra pyramidetta. Cerulli-Irelli, Fauna Mai. Mar., pt. V, p. 237, pl. XXI, fig. 23. 



This polymorphous shell is represented by a single specimen 

 7 millim. in height and 3 millim. in diameter. It is fusiform in 

 shape, with about six whorls which are a little convex, and in 

 general smooth, though faint indications of longitudinal folds are 

 visible in some places. The sutures are deep, making the whorls 

 look somewhat telescopic. Columella folds four, with the upper- 

 most the strongest; the others are somewhat distant from the 

 uppermost with the lowest very weak and hardly visible. Aper- 

 ture subrhombic, elongated. Canal short and recurved. The 

 general feature of the shell is like the Crag form, though not so 

 slender, in which respect our specimen looks more like fig. 336 of 

 Sowerby. The Crag species is said to have only a single 

 columella fold and is accordingly treated as var. uniplicata by 

 Wood. 



Fossil occurrence in Japan. — Koshiba Zone (Koshiba). 



Fossil occurrence in foreign countries. — Coralline Crag of 

 England, Pliocene of Italy, Miocene of France, Germany, Austria 

 etc, 



Living. — Mediterranean Sea and Atlantic coast of Northern 

 Africa. 



32. Mitra fusiformis, (Beocchi). 

 Pl. II. Fig. 6. 



Mitra fusiformis. Wood, Crag Moll., supplem., p. 8, pl. V, fig. 3 ab. Hörnes, Foss. Moll. 

 Wiener Beckens, vol. I, p. 98, pl. X, figs. 4-7. Cerulli-Irellt, Fauna Malac. Mariana, pt. V, 

 p. 235, pl. XXI, fig. 19. 



Yoluta fusiformis. Brocchi, Conch. Foss. Subap.. vol. II, p. 315, No. 16. 



A single specimen lacking the apex. In a perfect state, it 

 would have measured about 24 millim. in height. The whorls are 



