g6 Palaeontographica Americana 96 



PIRATE XIV 



Figure Page 



r. Area sca/arifi a Heilpnn 58 



Pliocene of Shell Creek, Florida; exterior of the valve figured on plate 13. A. 

 sra/arii/a is the finest of the Cunearcas and illustrates the tendency for the largest 

 members of several groups to appear in the Pliocene. 



2. Area scalarina Heilprin; Pliocene of Shell Creek, Florida; exterior of a right valve 

 lent by the U. S. National Museum. This figure and the preceding show the dif- 

 ferences between the two valves in form and sculpture. 



3. Interior of the same. 



4. Area ijuongrna Say 59 



Recent from Florida; exterior of a left valve. 



5. Interior of the same. 



6. Area incongrua Say; recent from Florida; right side showing the ribbing of the 

 right valve and the extension of the left valve beyond the right. 



7. Area incongrua Say; recent from Florida; umbonal view. Strips of the ligament are 

 torn off. There are no diagonal grooves, but the ligament tends to break up into 

 transverse strips when dry. 



8. Area brasiliana Lamarck S9 



Recent from Aspinwall. This figure shows the simulated sulcus on the anterior 

 side of the umbo. 



