RELATION OF WATKINS LAKE TO OTHER WATERS. 309 



before the water could escape over the plateaus either side of the north 

 end of the lake at a level under 900 feet. 



After the lake had attained by the northward recession of the ice-dam 

 a length of about twenty to twenty-five miles from Pine valley, it received 

 the overflow of the Hammondsport lake, and soon afterward it probably 

 received the waters of the Naples lake. If the receding ice-front held an 

 east-and-west trend across the region of these lakes, there must have 

 been a stage when the waters of the AVatkins lake coalesced with the 

 waters filling the Canandaigua and Keuka valleys upon the west, and 

 the Ithaca and perhaps other valleys on the east, up to the 900-foot 

 level. 



To this more widely expanded water at the Horseheads level, uniting 

 probabl}^ several of the local lakes, it seems desirable to give a non-geo- 

 graphic name, and the author proposes a name honored in American 

 geology and prominently identified with the glaciology of the Lauren- 

 tian lakes. Let it be known as lake Newberry. 



Possible Relation to Warren Waters. — The Horseheads channel is at present 

 the lowest and best developed of all the passes over the divide east of 

 lake Erie. At the time we are considering it was probably, by the de- 

 pression of central New York, the lowest outlet east of Chicago. Conse- 

 quently, if the vast Warren waters, into which all these local glacial lakes 

 were drained or with which they were blended, found, by the depression 

 of the region, any southward escape lower than Chicago while yet the 

 Mohawk valley was ice-covered, then the Horseheads pass was such out- 

 let. In this case lake Newberry retained its level as a part of the great 

 lake succeeding lake Warren. 



'D 



The Ithaca Lake. 

 cayuga valley. 



The geography of this valley and its glacial history is similar in gen- 

 eral to that of the Dansville valley and lake. Its proportions are on a 

 larger scale, but there is the bifurcation southward and the double lakes 

 in the beginning blending hiter into one. The lower outlet in the Ithaca 

 lake is, however, the eastern one.^^ 



Cayuga lake has a length of 38 miles and a breadth of one and a lialf 

 to three miles. Its altitude is 378 feet a])ove tide ; its depth more than 

 400 feet. Tlie main valley reaches about two miles farther south, to 

 Soutli hill, in Ithaca, where it divides. The main })ranch, or Cayuga 



*The topoKHipliy, ilrainagc and altitiule.s are well desoribed in "The Cayuga Flora," )>y Pro- 

 fessor W. R. Dudley, to whom the writer is indebted for many facts in the description of this 

 basin. Some of the figures of altitudes are changed to agree with later determinations. 



LIII-Rri.i.. (iv.nu Sor. ,\ji.. Vol.. C, IROt. 



