206 ALLAN HANCOCK PACIFIC EXPEDITIONS VOL. 6 



EXPLANATION OF PLATE 23 



Figs. 



1-3. Bolivina costata d'Orbigny. xl30. 



4. Bolivina compacta Sidebottom. x 130. 



5. Bolivina doniezi Cushman and Wickenden. x 160. 

 6, 7. Bolivina goudkoffi Rankin. 6, x 70. 7, x 90. 



8. Bolivina imbricata Cushman. x 120. 



9-11, 13-16. Bolivina interjuncta Cushman, var. bicostata Cush- 

 man. 9-11, IS, 16, X 70. 13, 14, X 90. a, front view; b, aper- 

 tural view. 



12. Bolivina interjuncta Cushman. x 90. a, front view; b, aper- 

 tural view. 



