TAB. XXI. 



Fig. 



1. Bulla cylindracea, page 175. 



a. view of aperture, var. vulgaris. 



b. var. monstrosa. 



c. view of apex of var. vulgaris. 



2. Bulla conulus, j. 173. 



a. front view. 



b. back view. 



c. view of apex. 



3. Bulla truncata, p. 176. 



a. front view. 



b. back view. 



c. view of apex. 



4. Bulla Regulbiensis, p. 177. 



#. front view, var. a. 



b. front view, var. |3. 



c. view of apex. 



5. Bulla Lajonkaireana, jo. 178. 



a. back view. 



b. front view. 



c. view of apex. 



6. Bulla concinna, j. 176. 



a. view of aperture. 



b. back view. 



c. view of apex. 



7. Bulla acuminata, jo. 174. 



#. front view. 



b. back view. 



c. end view. 



Fig. 



8. Bulla lignaria, p. 173. 



. back view. 



b. front view. 



9. Bullaea quadrata, p. 179. 



a. view of interior. 

 (5. view of exterior. 



c. end view. 



10. Bulleea sculp ta, p. 180. 



a. view of aperture. 



b. view of exterior. 



c. end view. 



11. Bullaea ventrosa, p. 182. 



# . view of aperture. 



b. view of exterior. 



c. end view. 



12. Bullaea scabra, jo. 181. 



a. view of aperture. 



b. view of exterior. 



c. view of apex. 



13. Bulla nana, p. 178. 



. back view. 

 b. front view. 

 (The small figure is the natural size.) 



14. Cleodora infundibulum, p. 191. <? 



indicate the size of the specimens. 



