Mesozoic and Camozoic Geology and Palaonfology. 247 



grandis, now Dispotoia grandis, Fissurella redimicula, 'Ostrea com- 

 pressirostra^ Pecten je-ffersonius, P. madisonius, P. cUntonius, P. sep- 

 tenarius, Plicatula marginata; and. from, strata now referred to the 

 Pliocene of Maryland, Area arata^ A. centenaria^ A. incile, Pectun- 

 culus subovafus, Nucula concentrica^ iV. laevis, Venericardia granu- 

 lata, now Cardita granulata, Crassatella undulata, Isocardiafraterna, 

 Tellina aequistriata^ Jjucina anodonta^ L. contracta, L. cribraria^ L. 

 suboMiqua, Venus deformis^ Astarte undulata, A. vicina^ Amphi- 

 desma subovatum, Corbula cuneata, C. maequalis, Panopcea rejlexa^ 

 Serpida granifera, and Dentalium attenuatum. 



In 1825, Dr. Richard Harlan* described, from Bigbone Lick, Ken- 

 tuck}^, Cervus americatius, Bos bombifrons, now Ovibos bombifrons, B. 

 lati/rons, now Bison latifrons; from a cave in Greenbriar county, 

 Virginia, Megalonyx jeffersoni^ and from Skidawaj^ Island, Georgia, 

 Megatherium cuvieri. 



In 1828, Dr. J. E. Deka^^f described, from the Post-pliocene at New 

 Madrid, on the Mississippi river. Bos pallasi. 



In 1829, Dr. Morton]; arranged, from the notes of Lardner Vanuxem, 

 some geological observations on the Tertiar^^ and Alluvial formations 

 of the Atlantic coast of the United States, showing their great extent 

 and inclination from Nantucket and Martha's Vineyard, on the coast 

 of New England, to the Mississippi river. The modern alluvial was 

 divided into vegetable mould and river alluvium; the ancient alluvial 

 into white siliceous sand and red earth; the Tertiary formation into 

 beds of limestone, buhrstone, sand and clay. He described, from 

 strata now regarded as Pliocene, Crepidula costata. 



In 1830, Mr. Timothy A. Conrad§ showed that Tertiary deposits 

 occupy all that part of Maryland south of an irregular line, running 

 from the vicinitj^ of Baltimore to Washington City, between the 

 Potomac river and Chesapeake bay, though most of the surface is 

 covered with a diluvial deposit of sand and gravel; and from the pres- 

 ence of Turritella mortoni, GucullcBa gigantea, and Venericardia 

 planicosta, he regarded the deposits in the vicinit}' of Fort Washing- 

 ton as contemporaneous with the London clay of England, which now 

 constitutes part of the Eocene of Europe, This was the first announce- 

 ment of the existence of strata, of this age, in America. 



* Fauna Americana. 

 f Am. Lye. Nat, Hist., N. Y., vol. ii. 

 t Jour. Acad. Nat. Sei., vol. vi., pt. 1. 

 g Jour. Acad. Nat. Sci., vol. vi., pt. 2. 



