596 



THE MIOCENE PERIOD 



Fig. 498. MIOCENE PELECYPODS: a and b, Area (Scapharca) slaminca Say; 

 c and d, Corbula idon:a Conrad; e, Crassatellites marylandicus (Conrad);/, Phacoidcs 

 (Pseudomilthd) foremani (Conrad); g, Tellina (Anguhis) producta Conrad; h, Leda 

 concentrica (Say); i, Modiolus dalli Glenn; j, Astarle thomasii Conrad; k, Ensis 

 directus (Conrad); /, Spisula (Hemimactra) marylandica Ball; m, Isocardia markoei 

 Conrad; n, Cardium (Cerastoderma) leptopleurum Conrad; o, Pecten (Chlamys) 

 madisonius Say; p, Venus ducatelli Conrad; q, Ostrea carolinensis Conrad. (Mary- 

 land Geol. Surv.) 



