4 
portions of New York and through nearly all New England, the an- 
nual rain-fall is from ten to fifteen inches greater. 
The natural botanical district, in which the City of Buffalo is 
situated, is a part of the basin of Lake Erie. For the sake of con- 
venience and distinction, it will here be called the Erte Districr. 
Towards the south and southeast, it finds its boundaries in a range 
of highlands, distant from thirty to fifty miles from Buffalo, beyond 
which the streams flow into the Allegany, and thence into the Ohio 
and the Mississippi. These highlands constitute, in fact, a part of 
the northeasterly limits of the Mississippi Valley. That region, so 
far as it comes within the scope of the Catalogue, will be called the 
ALLEGANY DISTRICT. 
In Chatauqua County, the limits of the Erie District are very 
narrow. Between Lake Erie and the head of Chataugua Lake, the 
interval of land is but seven and a half miles wide. Here the divid- 
ing ridge approaches so near Lake Erie as to leave only a strip of 
land less than four miles in width. Yet the summit of the ridge is 
891 feet above Lake Erie. Eastwardly its height increases. Between 
Chatauqua Lake and Connewango Creek the elevation is reached of 
1401 feet, and between Connewango Creek and Ellicottville, that of 
1570 feet. Upon the summit, in several places, a conglomerate of 
the coal period is found, zz place. In Chatauqua County, almost 
upon the crest of the dividing land, a series of lakes appears. The 
largest of these is Chatauqua Lake, 726 feet above Lake Erie.’ 
Northerly and northeasterly from Chatauqua Lake are Bear, Cassa- 
daga and Mud Lakes, respectively 755, 732 and 833 feet above Lake 
Erie, and as truly sources of the Mississippi as the far distant Itasca. 
The easterly boundary of the Erie District is another range of 
highlands, which divides it from the basin of the Genesee River:— 
here termed the GENESEE District. ‘Towards the southeast these 
elevations meet and unite with those which separate the Erie from 
the Allegany District, and are as high. To the north they decline, 
but even at Batavia they have an elevation of about 300 feet above 
Lake Erie. 
The northerly boundary of the Erie District is marked, both in 
New York and Canada, by that extraordinary exposure and eleva- 
tion of rock, known in its vicinity as the “ Mountain Ridge,” and-to 
which Canadian geologists have given the name of the “‘ Niagara 
