THE NATIONAL INSTITUTION. 



187 



Univalves. 

 Conns diluvianus, Green. 

 Cancellaria lunata, Conrad. 

 Cassis coelata, Conrad. 

 Dentalium dentalis, Lani. 

 Dispotfca costata, Say. 

 Dispotani grandis, Say. 

 Fusus tetricus, Conrad. 

 Fusus sulcosus, ConraJ. 

 B'usus rusticus, Conrad. 

 Fusus cinereus, Say. 

 Fusus quadricostatus, Say.- 

 Fusus parilis, Conrad. 

 Fusus strumosus, Conrad. 

 Fulgur coronatus, Conrad. 

 Fulgur fusiformis. 

 Fulgur canaliculatus. 



Bivalves. 



Artemis acetabulum, Conrad. 

 Astarte planutata, Conrad. 

 Amphidesma carinata, Conrad. 

 Area idonea, Conrad. 

 Cardium laqueatum, Conrad. 

 Cardita granulata, Say. 

 Corbula cunoata, Say. 

 Cijtherea Sayana, Conrad. 

 Isocardia rustica, Sow. 

 Lucina cribraria. Say. 

 Mactra pondcrosa, Conrad , 



Multivalves. 

 iBalanus proteus, Conrad. 

 Balanus ovularis. Lam. 



From all the various localities of this formation I have obtained about two hun- 

 drcd and thirty-nine species of shells and corals; among these I find thirty-six spe- 

 cies which are now existing on the coast of tfie United States. The number of 

 recent, compared with extinct forms, will therefore bring this formation within the 

 limits of the mioceno period. My only doubt, heretofore, has been that it could be 

 referred to the era of the Bordeaux deposits ; but since Mr. Lyell has suggested 

 that the latter may be an older portion of the miocenc than the crag of England, 

 which I have always regarded as identical in age with our medial tertiary, I have 

 no longer any objection to refer the formation in question to the miocene period. 

 I claim to have made this discovery solely by my own investigations. 



Post-Pliocenk Period. 

 Upper Tertiary Formation.— Ahoni one mile south of IlopcweU's Landing, on Iho 

 No. 2. 16 



Univalves. 

 Plcurotoma parva, Conrad. 

 Pleurotoma rotifera, Conrad. 

 Pleurotoma gracilis, Conrad. 

 Pleurotoma dissimilis, Conrad. 

 Scalaria clathrus. 

 Scalaria expansa, Conrad. 

 Terebra simplex, Conrad. 

 Terebra loxonema, Conrad. 

 Trochus humilis, Conrad. 

 Trochus reclusus, Conrad. 

 Turritella plebeia. Say. 

 Turritella variabilis, Conrad. 

 Typhis acuticosta, Conrad. 

 Voluta solitaria, Conrad. 

 Voluta mutabilis, Conrad. 

 Turritella laqueata, Conrad. 



Bivalves. 

 Mactra subcuneata, Conrad. 



Ostrea ? 



Pecten Madisonius, Say. 

 Pholas arcuata, Conrad. 

 Pholadomya abrupta, Conrad. 

 Saxicava rugosa ? 

 Solen ensis ? 

 Venus alveata, Conrad. 

 Venus Mortoni, Conrad. 

 Venus tetrica, Conrad. 



