EXPLANATION OP THE PLATES 
PLATE I. 
A topographical and geological map of Long and Staten islands, and of the Island of 
New-York. 
PLATE IL 
Fig. 1. Topographical sketch of Sand’s point and vicinity. 
2. Section of the above, across the beach, shov?ing the marsh mud under the beach. 
3. Topographical sketch of Oysterpond point and vicinity. 
4. Shows the position of the drift deposits, by a section. 
5. Shows the boulders on the beach and around the marsh, washed out by the surf. 
PLATE III. 
Fig. 1. Geological section on the island of New-York, parallel to the strike from Fiftieth- 
street to Brooklyn heights. 
2. The same, perpendicular to the strike across the island, showing the depth to the 
rock. 
3. Section of the Hudson slate rocks, contortion, etc.: J. Wickmin’s quarry, Lansing- 
burgh. 
PLATE IV. 
Fig. 1. Diagram illustrating the position of the materials of the east part of Long island. 
2. Section of the cliffs at Montauk point. Long island. 
3. Section half a mile west of Brown’s point, L. 1. 
4. Section 200 yards south of the same. 
5. and 6. Sections near the same, exposed by encroachments of the sea. 
7. Section 250 yards south, arched and unconformable strata, exposed by the storm 
of 12th October, 1836. 
8. Section three miles and a half west of Oysterpond point. 
9. Land-slide one mile and a half west of Brown’s point. 
A 
