extremity of Lake George, and then nearly due east to the east border of the state. The northerly division has five general subdivisions. The most westerly of these comprises all the streams flowing into Lake Erie and the Niagara River and those flowing into Lake Ontario west of the Genesee River. In Chautauqua County, the streams are short and rapid, as the watershed approaches within a few miles of Lake Erie. Cattaraugus, Buffalo, Tonawanda, and Oak Orchard creeks are the most important streams in this division. Buffalo Creek is chiefly noted for forming Buffalo Harbor at its mouth; and the Tonawanda for from its mouth was once used for canal navigation. Oak Orchard and other creeks flowing into Lake Ontario descend from the interior in a series of rapids, affording a large amount of waterpower. The second subdivision comprises the Genesee River and its tributaries. The Genesee rises in the northern part of Pennsylvania and flows in a generally northerly direction to Lake Ontario. Its upper course is through a narrow valley bordered by steep, rocky hills. Upon the line of Wyoming and Livingston counties, it breaks through a mountain barrier in a deep gorge and forms the Portage Falls. Below this point the course of the river is through a valley wide and bordered by banks high. At Rochester it flows over the precipitous edges of the Niagara limestone, forming the Upper Genesee Falls; and below it flows over the edge of the Medina sandstone, forming the Lower Genesee Falls. The principal tributaries of this stream are Canaseraga, Honeoye, and Conesus creeks from the south, and Oatka and Black creeks from the west. Honeoye, Canadice, Hemlock, and Conesus lakes—four of the Finger Lakes—lie within the Genesee Basin. The third subdivision includes the Oswego River and its tributaries, and the small streams flowing into Lake Ontario between the Genesee and Oswego rivers. The basin of the Oswego includes most of the inland lakes, which form a peculiar feature of the landscape in the interior of the state. The principal of these lakes are Cayuga, Seneca, Canandaigua, Skaneateles, Crooked, and Owasco lakes, all occupying long, narrow valleys, and extending from the level land in the center far into the highland region of the south (many of those lakes just mentioned are also part of the Finger Lakes). The valleys they occupy appear like immense ravines formed by some tremendous force that