24 G. D. Harris — Tertiary Geology of Maryland. 



Gastropoda. — Oliva sp. undt., Voluta typus, Fulgur coronatura, 

 Turritella indenta, Turritella exaltata, Crucibulum contractual, 

 Iniundibulum perarmatuai. 



From Zone d, Isocardia n. sp. and Venus n. sp. were ob- 

 tained. 



Section 4- — The bluffs are much lower at this locality, Zone 

 d being overlaid by only 10 feet of light barren sand. The 

 southerly dip is here recognizable, but it becomes much greater 

 a little farther south. 



Section 5. — In this section, all but the basal three feet of 

 Zone b has been removed by erosion, and the space refilled 

 with Pleistocene sand and gravel. From the remnant of this 

 zone the following species were obtained : Pecten madisonius, 

 Area subrostrata, Astarte varians, Yenus latilirata^ Dosinia 

 acetabular and a smooth Dentalium. 



Section 6. — The next good exposure seen on the bay shore 

 going south is about one mile below Plum point landing. 

 This is the locality designated as " Captain Hance's " in Con- 

 rad's article referred to above. Fossils are here very abundant, 

 but owing to their softness, it is difficult to obtain whole or 

 perfect specimens. The species enumerated in the following 

 table were all obtained from Zone b as it crops out along the 

 base of low bluffs a few hundred yards north of Section 6. 



Molluscan Species of Zone b, one mile south of Plum Point 

 Landing, Calvert County, Maryland. 



Pelecypoda. — Ostrea, sp., Anoruia, young, Pecten Humphreysii, 

 Pecten madisonius, Perna maxillata, Pinna muricata ?, Modiola, 

 fragment, Area subrostrata,* Byssoarca marylandica, Pectunculus 

 parilis, Nucula sp. nov., Leda sp., Leda sp. nov., Cardita granulata, 

 Astarte varians,* Astarte exaltata,* Astarte sp., Crassatella 

 melina,* Lucina subplanata,* Lucina anodonta, Lucina Foremani,* 

 Lucina crenulata,* Lucina sp., Chama congregata, Cardium lepto- 

 pleura,* Isocardia Markoei,* Isocardia sp. nov., Venus Ducateli 

 var. of mercenaria ?, Venus staruinea,* Venus latilirata,* Cytherea 

 marylandica var., Dosinia acetabula,* Tellina subreflexa, Tellina 

 sp., Semele carinata, Mactra sp., Mactra (Schizoderma), Corbula 

 cuneata, Corbula idonea,* Corbula elevata,* Saxicava sp. nov., 

 Pliolas ovalis, Panopgea goldfussii ? 



Gastropoda. — Actaeon fragment, Volvula iota ?, Cylichna sp., 

 Terebra simplex, small var., Pleurotoma marylandica,* Pleuro- 

 toma calvertensis ?, Pleurotoma bella-crenata.* Pleurotoma parva, 

 Pleurotoma sp., Cancellaria engonata,* Cancellaria sp., Oliva 

 literata, small, Volutella sp. nov., Scaphella solitaria,* Scaphella 

 typus, Fulgur coronatum, Fusus devexus, Fusus migrans, Ecphora 



* Mentioned also by Conrad, pp. 181-182; 2d Bull. Proc Nat. Inst, 1842. 



