Fossils from the Upper Musashino of Kazusa and Shimosa. 5! 



Fossil occurrence. — Shito (rare). 



52. Mitra pirula, Yokoyama. 

 PI. n. Fig. 9. 



Shell small, thick, shortly fusiform. Whorls about four and 

 n half, the first one and a half smooth and rounded rendering the 

 apex blunt and mamraillated, the remaining indistinctly shoulder- 

 ed with the surface above the shoulder slightly excavated, longitu- 

 dinally plicate. Plicse coarse, more or less unequal, indistinct or 

 obsolete on the body-whorl which is very large and about three 

 times as high as the spire. Periphery rounded. Ease rather 

 abruptly tapering downward into a sliort straight canal. Aperture 

 subsemilunar. Columella-folds four, somewhat oblique, the upper 

 three nearly equal in size and more or less parallel, the lowest 

 smaller and more oblique. Outer lip thin and simple, broadly 

 arcuate. Height 4 millim. Diameter 25 millim. 



A single specimen. It looks somewliat like the preceding 

 species, but is shorter and more inflated. 



Fossil occurrence. — Shito. • 



Family Fasciolarüdae. 



Genus FUSUS, Lamarck. 

 5S. ■ Fusus pet'plexus, A. Adams. 



Fusus perßexus. A. Adams, Journ. Limi. Soc, 1864, VII, p. 106. Pilsbry, Catalogue, 

 p. 26. Tryon, Man. Conch., Ill, p. 54, pi. 33, figs. 102-107. Tokuuaga, Foss. Env. 

 Tokyo, p. 6, pi. I, fig. 6. Yokoyama, Foss. Miuxa Peniu., p. 50, pi. II, fig. 17. 



Fksus inconstans. Lischke, Jap. Meerosconch., I, p. 34, pi. II, figs. 1-6, II, p. 26, pi. 

 Ill, figs. 1-5. Brauus, Geol. Env. Tokio, p. 55. 



Although not numerous, there are several fine specimens of 

 this shell so common among the living ones hitherto collected in 

 Central Japan. 



Fossil occurrence. — Otake, Tega, Shisui, Shito. Lower 

 Musashino of Naganuma. 



Living. — Northern, Central and Western Japan. 



