37G REED-WRIGHT— THE VERTEBRATES OF [October i. 



The principal tributaries of Cayuga Lake are : Cayuga Inlet, Six- 

 mile Creek, Cascadilla Creek, with a combined catchment area of 173 

 square miles, Salmon Creek, with a catchment area of 90 square 

 miles, and Taughannock Creek, with a catchment area of 60 square 

 miles. In their upper courses all these streams follow broad and 

 gently sloping preglacial valleys without waterfalls. All, however, 

 except the inlet, have cut a mile or more of post-glacial channel 

 just before entering the lake valley. Here the channels are narrow 

 and deep and the descent sudden, forming the gorges and waterfalls 

 so characteristic of the tributaries of Seneca and Cayuga lakes. 

 The fall of these streams in the last two miles (more or less) is be- 

 tween four and five hundred feet. What is said here of the princi- 

 pal tributaries applies to most of the streams entering Cayuga lake. 

 In this connection Professor Dudley wrote : 



There remains but one other feature to mention in this general review. 

 Nothing in the physical aspect of this region strikes the stranger as more 

 characteristic than the so-called gorges or ravines found in the first great 

 bench above the lake and valleys, wherever a creek or even a brook descends 

 to the lower level. The true gorges are probably, without exception, of recent 

 or post-glacial origin ; the walls are frequently of perpendicular or overhang- 

 ing rock from fifty to two hundred feet or even much higher, as in Taughan- 

 nock and Enfield ravines. Within these great chasms are usually falls or 

 cascades, some of them exceedingly beautiful and of considerable height. 



The Life Zones. — The Cayuga Lake basin is, in the main, typi- 

 cally Transitional, although in certain localities there is a trace of 

 the Upper Austral and Canadian. All of the nine species of mam- 

 mals, which, Miller'^ observes, " will serve to identify any part of the 

 Transition zone in New York," are found within the basin. These 

 forms are : 



Southeastern red squirrel, Sciurus hudsonicus loquax. 



Southern flying squirrel, Schiropterus volans volans. 



Northern pine mouse, Microtiis pinetorum scalopsoides. 



Naked-tailed mole, S.calops aquaticus. 



Hairy-tailed mole, Parascalops brezveri. 



Northeastern chipmunk, Tamias striatus lysteri. 



Bonaparte's weasel, Putorius cicognani. 



Big brown bat, Vespertilio fuscus. 



' Miller, Gerrit S., Jr., " Preliminary List of New York Mammals," Bull. 

 of the New York State Museum, Vol. VI., No. 29, 1899. 



