LIST OF ILLUSTRATIONS. XXI 
162. Position of the grooved limestone in the Clinton group, near Lewiston. 329 
163. Section of drift and more modern deposit. 339 
164. Section of drift on Lake Ontario. 340 
165. Weathered mass of hydraulic limestone. 341 
166. Alluvial hills and terraces. 342 
167. Section of modern detritus at Portage.,. 345 
168. Ridge road, division of. 350 
169. Terraced hill, Jefferson. 352 
170. Map of small ponds on Lake Ontario . 355 
171. Sandbar at outlet of stream. 356 
172. Discoloration of clay by percolating water. 362 
173. Tooth of Mastodon.363 
174. Lower falls of Portage. 368 
175. Section at Portage. 369 
176. Plan of river at Portage. 370 
177. Transverse section of the Genesee at Portage. 372 
178. Course of the Genesee river below Portage. 373 
179. Entrance of Wolf creek into the Genesee river. 374 
180. Elevation of strata by freezing water. 375 
181. Taghannuc falls, Tompkins county. 377 
182. Hector falls, Tompkins county. 379 
183. Falls on the Canaserowlie creek, Cattaraugus county. 380 
184. Section of rocks on the Genesee, below Rochester. 381 
185. Lower falls of the Genesee, Rochester. 382 
186. Section along the Niagara river. 383 
187. Transverse section of the Niagara river. 391 
188. Section along the Oak-orchard creek. 393 
189. Transverse section of Niagara at the falls. 397 
190. Conesus lake. 405 
191. Drift hills, Lockport. 440 
192. Section of strata at Lewiston, showing a depression filled with fragments from above 441 
LITHOGRAPHIC PLATES. 
Birdseye view of Niagara falls and river... 383 
View of Niagara falls, by Hennepin. 395 
Trigonometrical map of Niagara falls. 404 
TABLES OF FOSSILS USED IN THE DESCRIPTIVE PART OF THIS WORK, 
Numbered at the bottom from 1 to 66. 
