PLEIOCENE FOSSILS. 



PLATE XI. 



PECTENIDtE. 



Fig. 1. PECTEN EBOEETJS. Upper valve, natural size. Page 28. 



" 2. Lower valve. 



" 3. Side view of fossil. 



" 4. Outline of the ribs. 



" 5. Magnified view of a section of the ribs and interstices, showing the concentric undula- 

 ting lines. 



« 6. PECTEN COMPABILIS. Upper valve. Page 29. 



" 7. Lower valve. 



" 8. Side view of fossil, natural size. 



" 9. Outline of ribs. 



" 10. Magnified view of a section of the ribs and interstices, showing the concentric undula- 

 ting lines. 



