Plate 30 



Figs. 1-3. Polymorphina subrhombica Reuss. X 25. Eocene, Vincentown, N. J. 

 b, apertural view. 



4. Polymorphina aculeata d'Orbigny. (After d'Orbigny.) 



5. Polymor-phina longistriata Cushnian and Ozawa. X 25. (After Bur- 



rows and Holland.) Eocene, Thanetian, Pegwell Bay, England. 



6. Polymorphina parallela Millett. X 90. (After Millett.) Pliocene, 



St. Erth, England. 



7. Polymorphina alleni Cushman and Ozawa. X 60. Eocene, Brackle- 



sham bed XVII, White Cliff Bay, Isle of Wight, England, a, side 

 view; b, outline of end view. 



8. Polymorphina cushmani Plummer. X 25. Eocene, Midwayan, 5}4 



miles due south and very slightly west of Littig, Tex. a, side view; 

 6, apertural view. 



9. Polymorphina complanata d'Orbigny. X 35. Miocene, Tortonian, 



Amphistegina marl, Grunes Kreuz, Nussdorf, near Vienna, Austria. 

 a, side view; b, apertural view. 



10. Polymorphina advena Cushman. X 80. Lower Oligocene, Mint 



Spring marl, at waterfall in Mint Spring Bayou, Vicksburg, Miss. 

 a, side view; h, apertural view. 



11. Polymorphina frondea (Cushman). X 80. Lower Oligocene, Byram 



marl, Byram, Miss, a, front view; 6, apertural view. 



175 



