TAB. XXI. 



Fig 

 1, 



Bulla cylindracea, 7?(7ye 175. 



a. view of aperture, var. vulgaris. 



h. var. monstrosa. 



c. view of apex of var. vulgaris. 



2. Bulla conulus, j9. 173. 



a. front \-iew. 

 h. back view. 

 c. view of apex. 



3. Bulla truncata, ^. 176. 



a. front view. 

 h. back view. 

 c. view of apex. 



4. Bulla Regulbiensis, p. 177. 



a. fi-ont view, var. a. 



b. front ^^ew, var. j3. 



c. view of apex. 



5. Bulla Lajonkaireana, jo. 178. 



a. back view. 



b. front view. 



c. view of apex. 



6. Bulla concinna, jo. 176. 



a. view of aperture. 



b. back view. 



c. ^dew of apex. 



7. Bulla acuminata, />. 174. 



o. front \aew. 



b. back view. 



c. end \'iew. 



Fig. 



8. Bulla lignaria, //. 173. 



a. back view. 



b. front view. 



9. Bullsea quadrata, jo. 179. 



a. view of interior. 



b. view of exterior. 



c. end view. 



10. BuUsea sculpta,jo. 180. 



a. view of aperture. 



b. \aew of exterior. 



c. end view. 



11. Bullsea ventrosa, jo. 182. 



a. view of aperture. 



b. view of exterior. 



c. end view. 



12. Bullaea scabra, />. 181. 



a. view of aperture. 



b. view of exterior. 



c. view of apex. 



13. Bulla nana,ji9. 178. 



a. back view. 



b. front view. 



(The small figure is the natural size.) 



14. Cleodora infiindibulum, JO. 191. 



The lines indicate the size of the specimens. 



