Plate ï. 



Fig. 1. Retusa minima Yam. Enlarged, a. Front-view. b. Back-view. c. Apical 



view. Naganuma. p. 26. 

 Fig. 2. Volvula acuminata Brug. Enlarged, a. Front-view. b. Back-view. c. 



Apical view. Yokosuka. p. 36. 

 Figs. 3, 8. Bingicula musasbinoensis Yolc. Enlarged, a. Front-view. b. Back-view. 



Naganuma. p. 30. 

 Fig. 4. Cylicbna musàsbiensis Tok. a. Front-view. b. Apical view. Enlarged. Ko- 



sbiba. p. 27. 



Fig. 5. Cylicbna braunsi Yok. Enlarged, a. Front-view. b. Apical view. Naganuma. 

 p. 28. 



Fig. 6. Cylicbna sibaensis Yam. Enlarged, a. Front-view. b. Apical view. Mukai- 

 batake in Kami-Miyata. p. 28. 



Fig, 7. Cylicbna yamakawai Yok. Enlarged a. Front- view. b. Back-view. c. Apical 

 view. d. A part of tbe surface specially enlarged. Yokosuka. p. 29. 



Fig. 9. Cylicbna orientalis^Yok. Enlarged, a. Front-view. b. Back-view. c. Apical 

 view. Kosbiba. p. 30. 



Fig. 10. Terebra liscbkeana Dkr. a. Front-view. b. Back-view. c. A part enlarged, 

 Kami-Miyata. p. 31. 



Fig. 11. Terebra recticostata Yok. a. Front-view. b. Back-view. Naganuma. p. 32. 



Fig, 12. Terebra naumanni Yok. Enlarged, a. Front-view. b. Back-view. Naga- 

 numa. p. 32. 



Fig. 13. Terebra tokunagai Yok. Enlarged, a. Front-view. b. Back-view. Naga- 

 numa. p. 33. 



Fig, 14. Conns sieboldi Beeve. Front-view. Kosbiba. p. 34. 



Figs. 15, 16. Conus tuberculatus Yok. Enlarged, a. Front-view. b. Back-view. c. 

 Apical view. Kosbiba. p. 84. 



Fig, 17. Pleurotoma kamakurana Pils. a. Front-view. b. Back-view. Kosbiba. p. 35. 



Fig. 18. Pleurotoma mediocarinata Yok. Enlarged, a. Front-view. b. side-view. 

 Nojima. p. 36. 



Fig. 19. Pleurotoma (Surcula ?) nojimensis Yok. Enlarged, a. Front-view. b. side- 

 view. Nojima. p. 42. 



Fig, 20, Pleurotoma (Drillia) principalis Pils. a. Front-view. b. Side-view. Naga- 

 numa. p. 36. 



Fig. 21. Pleurotoma (Drillia) pseudoprinci palis Yok. Enlarged, a. Front-view. b. 

 Back-view. c. Side-view. Naganuma. p. 37. 



Fig. 22. Pleurotoma (Drillia) quantoana Yok. Enlarged, a. Front-view. b. Side- 

 view. Naganuma. p. 38. 



Fig. 23. Pleurotoma (Drillia) benten Yok. Enlarged, a. Front-view. b. Side-view. 

 Naganuma. p. 40. 



Fig. 24. Pleurotoma (Mangilia) desbayesii Dkr. Enlarged, a. Front-view. b. Side- 

 view, c. Side-view. Kosbiba. p. 41. 



Fig. 25. Pleurotoma (Drillia) braunsi Yok. Enlarged, a. Front-view. b. Back-view. 

 c. Side-view. Kosbiba. p. 40. 



Fig. 26. Pleurotoma (Drillia) cosibensis Yok. Enlarged, a. Front-view. b. Back- 

 view, c. Side-view. Kosbiba. p. 38. 



Fig. 27. Pleurotoma (Drillia) nivalioides Yok. Enlarged, a. Front-view. b. Back- 

 view. Kosbiba. p. 39. 



