TABLE OF CONTENTS. xxiii 
Page. 
Supplement to the quaternary system. 
Alluvial division. 
Various localities of marl. 229 
Various localities of peat.229 
On the origin of peat, by Dr. S. L. Mitchill . 229 
Bones of the mastodon in the Hudson valley.. 232 
Drifting sands; examples of changes of surface. 233 
Salt marshes; localities not before mentioned...234 
Beaches, spits and bars; localities not before mentioned.234 
Natural ice-houses “ “ ...235 
Subterranean streams “ “ .235 
Bursting of a pond. 235 
Shell banks of the coast of New-York.236 
Alluvial sandstone and conglomerate. 236 
Agaric mineral. 236 
Bog iron ore... 236 
Chalybeate springs. 237 
Infusoria. 237 
Land slide at Troy, 1842.. 
CHAPTER III. 
TERTIARY DEPOSITS. 
Slight modification of the system of arrangement in page 2 . 246 
Tertiary not certainly identified in the First District of New-York. 246 
Tertiary, if it exists there, is contained in the Long-island division.. 247 
CHAPTER IV. 
UPPER SECONDARY SYSTEM. 
1. Long-island division; 2. Trappean; 3. Red-sandstone division...248 
1. Lonc-island division . 248 
Composition, general characters, mineral and fossil contents...248 
Geological age. 248 
Location and extent in New-York. 248 
Mineral composition and texture, etc. exposed by means of a great storm.249 
hocal geology of Long-island division . 249 
Oysterpond point. 249 
Brown’s point and Petty’s bight. 249 
Geological periods indicated. 249 
Various phenomena described. 250 
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