PLEIOCENE FOSSILS 



PLATE XIII. 



PECTENIDiE. 



Fig. 1. PECTEN SEPTEISTAEIUS. Lower valve natural size. Page 31. 



" 2. Side view of Fossil. 



" 3. Magnified view of a portion of a rib. 



•" 4. Outline of the form of the ribs at margin. 



