Fig. I. Nucula (Acila) rfi-cwo. Conrad ; Pittsburg, Oregon; outside view; Ion. 24.6 



mm. ; p. 573. , 

 Fig. 2. Lucina plcsiolopha Dall ; Oligocene of Oak Grove, Florida ; interior of left 



valve; alt. 15.5 mm. 



Fig. 3. Nucula (Acila) dccisa Conrad, interior; Ion. 24.6 mm.; p. 573. 

 Fig. 4. Nucula (Acila) cordata Dall; Miocene of Oregon; Ion. 16.0 mm.; p. 573. 

 Fig. 5. Lucina plcsiolopha Dall, exterior; alt. 15.5 mm. 

 Fig. 6. Nucula Shalcri Dall; Miocene of Gay Head, Martha's Vineyard, Massachusetts; 



Ion. 16.5 mm. ; p. 575. 

 Fig. 7. Cardiuni dritidiciim Dall; Oak Grove sands; exterior of left valve; Ion. 25 



mm. ; p. 1094. 

 Fig. 8. Cardium chifolanum Dall; Chipola marl; exterior of right valve; alt. 36 mm.; 



p. 1098. 

 Fig. 9. Cardiuni tafhriiiin Dall, exterior of left valve; Oak Grove sands; Ion. 35 mm.; 



p. 1098. 



Fig. 10. Cardium (Fragum) arcstum Dall; Caloosahatchie beds; alt. 27 mm.; p. 1102. 

 Fig. ii. The same from behind; alt. 27 mm. 

 Fig. 12. Cardium (Trigoniocardia) alicula Dall, a worn pseudomorph from the Ballast 



Point silex beds; alt. 13 mm.; p. 1103. 



Fig. I2b. Astyris turgidula Dall; Ballast Point. Tampa Bay, silex beds; alt. 13 mm. 

 Fig. 13. Cardium ctcnolium Dall; Oak Grove sands; alt. 20 mm.; p. 1081. 

 Fig. 14. Cardium faiisatnini Dall: Oak Grove sands; Ion. 12.3 mm.; p. 1093. 

 Fig. 15. Cardium (Hemiciirdinin) afatcticum Dall; Oak Grove sands; outside of left 



valve; alt. 10.5 mm.; p. 1105. 

 Fig. 16. Cardita sp. ; Oak Grove sands ; Ion. 20.5 mm. ; young shell. 



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