24 



PROCEEDINGS OF THE ACADEMY OF 



[1880. 



22 Modiola Ducatelii, 29 Perna maxillata, 



23 Ostrea percrassa, 30 Pholas ovalis, 



24 Panopseaporrecta(Goldfiissi) (= P. costata?) 



25 Pecten Humphreysii, 31 Tellina lenis, 



26 " Madisonius, 32 Veiius alveata, 

 2*7 Pectimculus parilis, 33 " staminea, 

 28 " lentiformis, 34 " 3Iortoni? 



NEWER PERIOD. — J^ PATUXENT GROUP. 



1 Anomia Conradi, 13 



(= A. ephippium ?), 



2 Area idonea, St. M., 14 



3 Artemis acetabulum, St. M., 15 



4 Astarte undulata, St. M. 16 



5 Cardita protracta, 11 



6 Cardium laqueatum, St. M., 



1 Carbula idonea, St. M., E., 18 



8 Crassatella Marylandica, E., 19 



9 Gytherea Saijana, St. M., 20 



10 " Marylandica, 



11 » albaria, 21 



12 Isocardia fraterna, St. M., 22 



Lucina Americana, E., 



(= L. Floridana), 

 Mactra incrassata, 

 Mya producta, 

 Panopsea Americana, 

 " porrecta (Gold- 



fussi), St. M. 

 Pecten Madisonius, St. M., E. 

 Petricola centenaria, 

 Pholas ovalis, 



(= p. costata ?), St. M. 

 Tellina biplicata, E., 

 Vemis Mortoni ? St. M. 



II. ST. MARy's GROUP. 



1 Amphidesma carinata,f 



2 " subovata,f 



3 Area idonea, 



4 " arata,f 



5 " stilicidium,f 



6 Artemis acetabulum, 

 T Astarte undulata, 



8 " planulata,t 



(^= A. perplana '(). 



9 '' vicina.f 



10 Cardita granulata,t 



11 Cardium laqueatum, 



12 Corbula inequalis,f 

 13* " cuneata,! 



14 Corbula idonea, 



15 Gytherea Say ana ^ 



16 " 



{Artemis) concen- 

 trica,f 



{^ A. elegans /). 

 Isocardia fraterna, 

 Lucina cribraria,f 



IT 



18 



19* Mactra ponderosa,f 



20 



21 



22 



23 



24 



25 



" subcuneata,f 

 " fragosa,f 

 " delumbis,f 

 Ostrea Virginica,f 

 Panopjea porrecta, 

 Pecten Madisonius, 



* Corbula cuneata and Mactra ponderosa are also found in the newer 

 deposits of Calvert Covinty, iiear Cove Point. 



