XVI 
CONTENTS. 
CHAPTER XXL 
LAKES. 
Lakes of the district, their geological situation, etc. 405 
Elevation and depression of water in the great lakes.. „ .. 408 
Mean length, breadth, elevation and area of the several great lakes. 411 
Elevation of the smaller lakes. 412 
Elevation of different points in the district, from Lake Ontario southward.413 
CHAPTER XXII. 
Local geology and economical products of the counties comprising the Fourth Geological District, 414 
Wayne county... 414 
Monroe county. 422 
Orleans county. .. 433 
Niagara county . 440 
Seneca county. 449 
Ontario county. 453 
Yates county. 458 
Livingston county. 459 
Genesee county. 464 
Erie county .. 469 
Tompkins county (western half) . 475 
Chemung county. 477 
Steuben county. 480 
Allegany county . 484 
Cattaraugus county. 488 
Chautauque county... 493 
CHAPTER XXIII. 
On the identity of the rock formations of the western States with those of New-York. 500 
CHAPTER XXIY. 
On the identity of New-York formations with those of Europe. Table of Equivalents in Ameri¬ 
can strata. 516 
CHAPTER XXV. 
CONCLUSION. 
