PLATE LVII1. 



Fig. i. Oliva liodes Dall ; Chipola Oligocene; alt. 27.0 mm.; p. 1576. 



Fig. 2. Columbella cosmia Dall ; Pliocene marl of Shell Creek, Florida ; alt. 13.5 mm. ; 

 p. 1607. 



Fig. 3. Olivella eutacta Dall; Chipola Oligocene; alt. 15.0 mm.; p. 1576. 



Fig. 4. Oliva (Omogymna) Martensii Dall ; Chipola Oligocene ; alt. 19.5 mm. ; p. 1576. 



Fig. 5. Rhynchonella salpinx Dall, haemal view; Eocene of Wilmington, North Caro- 

 lina ; Ion. 8.2 mm. ; p. 1535. 



Fig. 6. The same, viewed from in front. 



Fig. 7. The same, viewed from the side; a, the line of junction of the deltidial plate 

 with the valve. 



Fig. 8. Argyrotheca Schucherti Dall; Miocene of Jackson Bluff, Florida; lat. 5.8 mm.; 

 P- 1539- 



Fig. 9. Ringicula chipolana Dall, Proc. U. S. Nat. Mus., xviii., 1895, p. 25 ; Chipola 

 Oligocene of Florida. 



Fig. 10. Rhynchonella Holmesii Dall, anterior view ; Eocene of Wilmington, North 

 Carolina; p. 1536. 



Fig. ii. The same, haemal valve of adult; lat. 10.0 mm. 



Fig. 12. The same, young, the beak slightly defective; alt. 7.0 mm. 



Fig. 13. Discinisca lugubris Conrad, basal valve; seen from above, the posterior portion 

 partly defective; Miocene of Virginia; lat. 13.5 mm.; p. 1534. 



Figs. 14-20. Terebratula wilmingtonensis Lyell and Sowerby; 14, young shell, smooth, 

 alt. 27.0 mm.; 15, next stage, showing inception of crenulations, alt. 29.0 

 mm. ; 16, basal view of 17 ; 17, full-grown specimen with strong crenations, 

 alt. 36.0 mm. ; from the ventral valve of a specimen of this sort Ravenel 

 probably described his T. canipes; 18, adult specimen with hardly any crena- 

 tion, alt. 35.0 mm. ; 19, very narrow specimen, alt. 36.0 mm. ; 20, large adult 

 of unusual breadth and only faint indications of a tendency to crenulate, 

 alt. 40.0 mm.; all from Eocene limestone of Wilmington, North Carolina; 

 p. IS37- 



1631 



