88 APPENDIX. 
No. V. 
In appending a catalogue of Tertiary shells, it has been thought best to employ 
the following nomenclature of the strata to which they belong: 
Upper Tertiary, Newer Pliocene, or Quaternary, 
Middle Tertiary, or Upper Marine,* 
Lower Tertiary, or Eocene. 
Mr. Conrad found the following shells in the Newer Pliocene on the Potomac, 
about three miles from its mouth: 
UNIVALVES. 
Acteon melanoides, Conrad ; Crepidula convexa, Say; C. glauca, Say; Fusus 
cinereus, Say; Nassa obsoleta, Say; N. trivittata, Say; Natica duplicata, Say; 
N. interna, Say; Ranella caudata, Say; Scalaria. 
BIVALVES. 
Arca transversa, Say; A. ponderosa, Say; Corbula contracta, Say; Rangia 
cyrenoides; Cytherea Sayana, Conrad; Mactra lateralis, Say; Mya arenaria; 
Mytilus hamatus, Say; Nucula levis, Say; N. acuta, Con.; Pandora trilineata, 
Say; Petricola pholadiformis, Lam.; Pholas costata, Lam.; Sanguinolaria fusca, 
Con.; S. lusoria, Con.; Solecurtus caribeus; S. ensis, Lin.; Venus mercenaria, 
Lam.; Venus. 
In the preceding list, but three species occur which have not been satisfactorily 
identified with existing shells of the middle and southern coasts. 
In addition to these, the Colombella avara of Say and some other species were 
found in digging a well in the city of Charleston. They are in Professor Rave- 
nel’s collection, and are as brilliant in their colors and polish as living shells. No 
extinct species was found among them. 
* See note at the end of the following catalogue. 


