Plate 31 



Figs. 1-6. Polymorphina charlottensis Cushman. 1, Pliocene, Timms Point, San 

 Pedro, Calif. X 25. a, b, side views; c, apertural view. 2-6, 

 upper Pliocene, Natsukawa, Province of Echigo, Japan, showing 

 early stages in development. X 45. 



7. Polymorphina lingulata Stache. X 20. (After Stache.) a, front 



view; b, end view. 



8. Polymorphina schlumbergeri Cushman and Ozawa. X 45. Miocene, 



Aquitanian superieur, St. Avit, near Mont de Marson, near 

 Bordeaux, France, a, side view; b, apertural view. 



9. Polymorphina howchini Cushman and Ozawa. X 25. Lower Plio- 



cene, McDonald's, Muddy Creek, Hamilton, Victoria, Australia. 

 a, side view; b, basal viev>f. 

 10. Polymorphina frondiformis Searles Wood. X 25. Pliocene, Crag 

 Sutton, England, a, side view; b, apertural view. 



176 



