Fossils t'roui the Upper Musashino of Kazusa and Shimosa. 53 



This species already described from the Lower Musashino is 

 represented by better preserved specimens some of which are larger 

 than that figured by Smith. 



The fossil is up to 33 millim. in height and 11 niiilim. in 

 diameter, moderate in thickness, and quite fusiform. The whorls 

 number about seven and a half, of which the first one and a half are 

 embryonal, smooth and raainmillary, the remaining sloping above 

 and convex below, somewhat contracted at the lower suture, longi- 

 tudinally plicate and spirally striate. Tlie plicae are obtuse, broad, 

 wider than intervals and rather indistinct on the last part of the 

 body-whorl. The num])er is variable, but in a specimen of 30 

 miUim. in lieiglit it is between twelve and fifteen. The spiral striae 

 are equal, there being generally three coarse ones on the convex 

 part of the whorl which on crossing the plicae elevate themselves 

 into transversely elongated tubercles, a character most distinct in 

 adult specimens. The finer striae which cover the sloping shelf 

 and the interspaces between the coarser ones are often unequal, 

 especially on the body-whorl which is provided with more than ten 

 tuberculated striae, the tubercles becoming indistinct and finally 

 obsolete toward the caudal end of the base. The aperture is ovate 

 with the inner lip covered with a thin glaze. Outer lip thin, 

 crenate at margin. Canal long, somewdiat oblique. 



Fusus suöoblUus Pilsbry is undoubtedly a species founded on a 

 specimen of Fusus niponicus more grown (the height is given as 

 36.5 millim.) than the present fossil. 



Not rare. 



Fossil occurrence. — Shito. Lower Musashino of Miyata and 

 Koshiba. 



Living. — Central Japan (Smith gives the locality as south of 

 Honshu at r)2 fathoms). 



Family Buccinidae. 



Genus CHRY80D0.>1US, Swainson. 



56. ffhryso(loitH€s arfhrifict€s, (Valenciennes) Bernardi. 



PI. ir. Fig-. 12, 



ChrysodoniKs arthntiGus. Pilsbry, Catalogue, p. 28. 



Neptxmea arthritica. Dunker, Index Moll, p. 14. Liscbke, Jap. Meeresconch., I, p. 37. 

 Brauns, Geol, Env. Tokio, p. 28, pi. II, fig. 1. 



