172 
THE GEOLOGIST. 
much higher antiquity than the gravel containing the bones of 
the Mastodon at the Falls. 
Rochester. — In the suburbs of this city remains of the Mas- 
todon giganteum were found associated with existing species of 
Mollusca in gravel and marl below peat. 
Genesee. — Here remains of the Mastodon giganteum were 
found with existing shells^ in a small swamp in a cavity of the 
boulder formation, so that the animal must have sunk after the 
period of the drift, when a shallow pond fed by springs was in- 
habited by the same species of freshwater mollusca as now live 
on the spot. 
Albany and Greene Counties. — Mr. Lyell examined, in com- 
pany with Mr. Hall, two swamps west of the Hudson River, 
where the remains of Mastodon occurred in both places at a 
depth of four or five feet, precisely in such situations as would 
yield shell marl, and peat, with remains of existing animals in 
Scotland. Cattle have recently been mired in these swamps. 
According to Mr. Hall the greatest elevation at which Mas- 
todon bones have been found in the United Srates is at the 
town of Hinsdale, situated on a tributary of the river Allegany 
in Cattaraugus county in the State of New York, where they 
occur at an elevation of 1500 feet above the level of the sea. 
Maryland. — In the museum at Baltimore, Mr. LyeU was 
shown the grinder of a Mastodon, distinct from M. giganteum, 
and which had been recognised and labelled by Mr. Charles- 
worth as M. longirostrisy Kaup. It was found at the depth of 
15 feet from the surface in a bed of marl near Greensburgh, in 
Carolina County, Maryland, and is considered by Mr. Lyell as 
a miocene fossil. 
Atlantic border. — Between the Appalachian mountains and 
the Atlantic there is a wide extent of nearly horizontal tertiary 
strata, which at the base of the mountains are 500 feet and up- 
wards in height, but decline in level nearer the ocean and at 
