Plate XIII. 



Figs. 1-3. Pecteu irregularis Sow. 1. Left valve. 2, 3. Right valves. Koshiba. 



p. 153. 

 Figs. 4-6. Pecteu nagauumaua Yok. 4. Right valve. 5, 6. Left valves. Naganuma. 



• p. 160. 

 Figs. 7, 8. Pecten cosibeusis Yok. 7. Right valve. 8. Left valve. Koshiba. p. 156. 

 Figs. 9, 10. Pecten iutuscostatus Yok. Somewhat enlarged. 9. Left valve. 10. 



Right valve, a. Outside, b. Inside. Kami-Miyata. p. 156.: 

 Figs. 11-13. Pecten vesiculosus Danker. 11, 13. Left valves. 12. Right valve. 



Koshiba. p. 154. 

 Figs. 14, 15. Pecten yessoensis Jay. 14. Right valve. 15. Left valve. Koshiba. 



p. 159. 



