PLATE LI. 

 Fig. I. Divaricella quadrisulcata Orbigny; from the Miocene of Petersburg, Virginia; 



Ion. 18.5 mm. ; p. 1389. 

 Fig. 2. Divaricella chipolana Dall ; from the Oligocene bed at Alum Bluff, Florida ; 



Ion. 18.5 mm.; p. 1389. 

 Fig. 3. Divaricella compsa Dall; from the Pliocene marl of Shell Creek, Florida; 



Ion. 11.5 mm.; p. 1391. 

 Fig. 4. Codakia (Jagonia) pertenera Dall ; from the Oligocene marl of Bowden, 



Jamaica ; Ion. 37.0 mm. ; p. 1347. 

 Fig. 5. Cyrenoida caloosaensis Dall ; from the Pliocene marl of the Caloosahatchie 



River, Florida; Ion. 31.0 mm.; p. 1335. 

 Fig. 6. Lucina santarosana Dall ; from the uppermost Oligocene sand at Oak Grove, 



Florida ; Ion. 39.0 mm. ; p. 1354. 

 Fig. 7. Lucina corpulenta Dall ; from the Chipola Oligocene, Florida ; Ion. 42.0 mm. ; 



P- 1354- 



Fig. 8. The same, umbonal view. 

 Fig. 9. Lucina janus Dall ; from the Chipola Oligocene, Calhoun County, Florida ; 



Ion. 42.0 mm. ; p. 1353. 

 Fig. 10. Phacoides (Miltha) heracleus Dall; from the Chipola Oligocene; Ion. 77.0 



mm. ; p. 1376. 

 Fig. ii. Phacoides (Miltha) chipolanus Dall, restored from fragments of the opposite 



valve; from the Chipola Oligocene; Ion. 71.0 mm.; p. 1375. 



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