1909.] THE CAYUGA LAKE BASIN, N. Y. 371 



The Maps. — The map of the Ithaca region (PI. XVII) is from 

 Dudley's " The Cayuga Flora." It shows this region in more detail 

 than the general map. A small portion of the southern end of the 

 basin is shown in a photograph (PI. XVIII) of a relief map made 

 by William Stranahan from the U. S. Geological Survey sheets. It 

 gives a very accurate idea of the gorges and general surface carving 

 in the southern portion of the basin. It is through the courtesy of 

 Mr. Stranahan and the authorities of the Cornell University Library 

 that we are able to reproduce it here. Plate XIX represents a cross- 

 section of the finger-lake region, showing the comparative depths and 

 altitudes of lake levels and the altitude of intervening land. The 

 lakes are represented in section at their deepest points, the land as 

 indicated by the lines A, B, C on the figure in the lower left-hand 

 corner of the plate. The distance between the lakes is not propor- 

 tional to the elevation. Plate XX is a map of the lake region of 

 central New York based primarily upon the map published by Pro- 

 fessor Dudley in his flora of the basin. It has been modified in 

 many particulars in order to adapt it to the needs of the present 

 paper. The modifications are based largely upon the maps of the 

 U. S. Geological Survey and in a minor degree upon personal obser- 

 vations. The number accompanying the name of a town or hill 

 indicates its altitude above sea level. The altitudes are taken from 

 bench marks so far as they are given. In other cases the altitude 

 given is that of the contour which passes through the center of a 

 town or indicates the top of a hill. 



The Lake Basin. — Cayuga is the largest of a series of approxi- 

 mately parallel lakes in central New York which extend in a north 

 and south direction. They are long and narrow, virtually deep 

 river valleys, and consequently have been very appropriately des- 

 ignated the " Finger Lakes." The basin as delimited in this paper 

 (PI. XX) comprises about i,6oo square miles. Throughout the 

 greater part of this area only the actual catchment basin has been 

 included, but, in the northern portion, the limits as we have set them 

 are, to a certain degree, arbitrary. It includes a portion of the 

 Clyde and Seneca rivers and the large Montezuma marshes which 

 cover an area of 45 square miles. 



The greatest length of the basin is about 65 miles, extending 



