TAB. XXI. 



Fig. 



8. Bulla lignaria, 7/. 173. 



a. back view. 



b. front view. 



9. BuUsea quadrata,/i. 179. 



a. view of interior. 



b. view of exterior. 



c. end view. 



10. Bullsea sculpta, JO. 180. 



a. view of aperture. 



b. view of exterior. 



c. end view. 



11. Bullsea ventrosa, JO. 182. 



a. Adew of aperture. 



b. view of exterior. 



c. end view. 



12. Bullsea scabra, /J. 181. 



c. view of aperture. 



b. view of exterior. 



c. view of apex. 



13. Bulla nana, JO. 178. 



a. back view. 



b. front view. 



(The small figure is the natural size.) 



14. Cleodora infundibulum, JO. 191. 



The lines indicate the size of the specimens. 



