32 Art. 6.— M. Yokoyama : 



Fossil occurrence: — Miyata Zone (Kami-Miyata). Upper 

 Musashino of Shimosa. 



Living: — Central Japan (Sagami Bay). 



10. Terebra recticostata, Yokoyama. 

 Pl. I. Fig. 11. 



Shell subulate; whorls about twelve, of which the two upper- 

 most are embryonal and smooth; the others are only slightly 

 convex with a subsutural band of coarse tubercles numbering 

 thirteen on the penultimate and fourteen on the ultimate whorl. 

 Below these tubercles there are rounded vertical ribs just as many 

 as the tubercles, separated from them by a wide though shallow 

 transverse (spiral) groove in the bottom of which there is an 

 impressed transverse (spiral) line more distinct in the upper than 

 in the lower whorls. The ribs which become weak at the lower 

 suture and almost obsolete on the base of the last whorl below the 

 rounded periphery are separated from each other by a concave 

 interspace which is more than double the breadth of the ribs. 

 Growth-lines distinct. Aperture sul »rhombic. Canal short, bent. 

 A short posterior canal is also present. Columella lip somewhat 

 flattened and depressed with a median longitidudinal groove. 

 Outer lip thin and sharp. A single specimen obtained measures 

 2-1 millim. in height and G millim. in diameter. 



This species somewhat resembles Terebra serotina Ad. and 

 Reeve (Voy. Samarang, p. 30, pl. X, fig. 12), but the ribs are 

 less in number and the groove below the tubercular band broader. 



Fossil occurrence: — Naganuma Zone (Naganuma). Upper 

 Musashino of Shimosa. 



11. Terebra naumanni, Yokoyama. 

 Pl. I. Fig. 12. 



Shell subulate; whorls many, slightly concave, with two 

 somewhat elevated suturai bands carrying tubercles, the one close 

 to the upper suture and the other close to the lower. The two 

 bands are unequal in breadth, the lower being nearly twice as 



