Plate VI. 



Calliostoma sagamianum Yok. Enlarged, a. Front-view. b. Back-view. 



Naganuma. p. 93. 

 Euchelus feaestratus Yok. Enlarged, a. Front-view. b. Back-view. 



Yokosuka. p. 94. 

 Macroschisma sinensis A. Ad. Enlarged. Yiew from above. Otsu. p. 96. 

 Mitra emmae Yok. Enlarged, a. Front-view. b. Back-view. Shimo- 



Miyata. p. 49. 

 Umbonium gigantemn Less. Back-view. Naganuma. p. 94. 

 Umbonium costatum Val. Front-view. Naganuma. p. 95. 

 Puncturella subconica Yok. Enlarged, a. Side-view. b. From above. 



Koshiba. p. 97. 

 Cyclostrema duplicatum Lke. Enlarged, a. Front-view. b. View from 



below, c. View from above. Naganuma. p. 95. 

 Acmaea kuragiensis Yok. Enlarged, a. From above, b. From side. 



Kosbiba. p. 10.0 

 Emarginula fragilis Yok. Enlarged, a. Side-view. b. From above. 



Sbimo-Miyata. b. 98. 

 Acmaea nojimensis Yok. Enlarged, a. From side. b. From above. 



Nojima. p. 100. 

 Acmaea heroldi Dkr. Enlarged, a. From above, b. From side. Otsu. p. 99. 

 Figs. 13, 14. Tropbon subclavatus Yok. Front-views. Shimo-Miyata. 

 Fig. 15. Emarginula sp. Enlarged, a. From side. b. From above. Kosbiba. p. 99. 

 Fig. 16, 17. Helcioniscus pallidus Gld. a. Side-views, b. From above. Kosbiba. 



p. 101. 

 Fig. 18. Fissuridea cf. tanneri Verr. a. From above, b. From side. Kosbiba. p. 96. 

 Figs. 19, 20, 21. Dentalium weinkauffii Dkr. 21. Young specimen. Sbimo-Miyata. 



p. 102. 

 Figs. 22, 23, 24. Dentalium octogonum Lam. Naganuma. p. 103. 

 Figs. 25, 26. Cadulus gordonis Yok. Right-band figures enlarged. 25. Okine. 



26. Naganuma. p. 104. 

 Fig. 27. Dentalium complexum Dall. Kosbiba. p. 101. 



Fig. 28. Dentalium edoense Tok. Okine. Right-hand figure enlarged, p. 103. 

 Fig. 29. Pbolas fragilis Sow. Bight valve, a. Inside, b. Outside. Otsu. p. 104. 

 Figs. 30, 31. Pboladomya japonica Yok. a. Right valves. 31 b. Left-valve. 30 b. 

 31 c. Views from above. Naganuma. p. 106. 



