■](, PALAEONTOGRArHICA AMERICANA 76 



PIRATE IV 



Figure Plate 



1 . Area propalicla Conrad 1 8 



After Conrad. 



2. Area virginiae Wagner 19 



Miocene of Claremont Wharf, James River, Virginia; specimen with grooved 

 ribs. 



3. Area virginiae Wagner; Miocene of Claremont Wharf, James River, Virginia; speci- 

 men with plain ribs. The anterior ribs are obscured by the lighting. 



4. Interior of the same, showing the slightly granular teeth. The teeth of the valve 

 used for fig. 2 are not at all broken up. Area virginiae appears to be related to 

 Afra idonea. 



5. Aiea eenicnaria Say 19 



Miocene of James River, Virginia. 



6. Area eente7ie,ria Say; Miocene of James River, Virginia. This shows the long, ele- 

 vated muscle scars and hollow teeth. 



7. Area eentenaria Say; Miocene of Kingsmill, Virginia. Remnants of the ligament 

 still cling to the cardinal area. They are transversely grooved. 



8. Area retienlata Gmelin 20 



Recent from Panama; X 2; a highly ornamented form. 



9. Area reticulata Gmelin; recent from Panama; natural size; umbonal view showing 

 the posterior ribs rising along the umbonal ridge and the ligament covering only 

 the posterior half of the cardinal area. 



10. Area retienlata Gmelin; recent from Trinidad; X 2; a form with the concentric 

 sculpture predominant. Anteriorly the radial ribs are stronger, but this is obscured 

 in the photograph. 



1 1 . Interior of the same. 



12. Area retienlata Gmelin; recent from Paumotus; natural size; oblique view to show 

 how the posterior ribs of this species rise along the umbonal ridge. 



13. Area millifila Dall 21 



"Pliocene of Shell Creek, Florida; Ion. 18.5; diam. lo.omm."; after Dall. 



14. Area 7nillifila Dall; "PHocene marl of Shell Creek, Florida * * *."; after Dall. 



15. A rca itiornata Meyer 21 



After Meyer. The indicated height of the figured specimen is 4 mm. The new 

 name of this species is A. Harrisi. 



16. Area ^rfaw^/ (Shuttleworth) Smith 22 



Pliocene of the Croatan beds. North Carolina; X 4. This valve shows rows 

 of blisters and the smoothness of the shell where the blisters are worn off. 



17. .4;rfl ^rfa;;/« (Shuttleworth) Smith; Miocene of Curry, North CaroHna; X 4 ; inter- 

 ior, showing the gap in the teeth opposite the ligament. 



18. Area Adamsi (Shuttleworth) Smith; recent from Cuba; natural size; umbonal 

 view, to show the size and position of the ligament in Fossiilana. 



