292 



GEOLOGY. 



Fig. 457. — Miocene Pelecypods: a and 6, Area (Scapharca) staminea Say; c and d 

 Corbula idonea Conrad; e, Crass tellites marylandicus (Conrad); /, Phacoides (Pseu- 

 domiltha) foremani (Conrad); g, Tellina (Angulus) producta Conrad; h, Leda con- 

 centrica (Say) ; i, Modiolus dalli Glenn; j, Astarte thomasii Conrad; k, Ensis directus 

 (Conrad); I, Spisula (Hemimactra) marylandica Dall; m, Jsocardia markoei Conrad; 

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

 Say; p, Venus ducatelli Conrad; q, Ostrea carolinensis Conrad. (After Maryland 

 Geological Survey.) 



i 



