24 NEW YORK STATE MUSEUM 



exemption seems to be as follows. Until the lobate ice front had 

 receded from the Cattaraugus valley as far as Shirley in this dis- 

 trict the waters in the Cattaraugus embayment were held as high- 

 level lakes, having their outlets across the slopes north and north- 

 west of Perrysburg. In this case no stream flow could occur 

 along the ice front in the Shirley district or on the slopes north of 

 Gowanda until the lake waters were drained to a level lower than 

 the ice border. The kames (knolls of sand and gravel) which are 

 scattered over the slope from Collins north to Shirley were pro- 

 duced by glacial streams debouching into standing water that 

 faced the ice border. The reader will appreciate how such phen- 

 omena as these, along with the relationship in series of the 

 stream channels and deltas, enable us to determine the position 

 of the receding ice front and to find the relationship or correlation 

 of the several features. 



On the road leading east from Shirley there are some weak scour- 

 ways which suggest glacial drainage, but are not strong enough 

 to map with confidence. Northeast of Shirley and east of North 

 Collins some scourways, not very strong, are indicated on the map 



[pl- 4]- 



The lowest stream work at North Collins is a steep bank facing 

 the Whittlesey beach east and south of the village, at altitude about 

 850 feet. The highest channel noted is 2 miles east of the village, 

 near four-corners, with altitude over iioo feet. 



At the three-comers i^ miles south of Eden are interesting 

 channels cut in black shale, with remnants of the rock left as 

 islands or outliers. One mass is exactly at the corners; another 

 lies south with a ridge form; and small ones occur on the west 

 side of the road. 



The Whittlesey shore in this section lies frequently along cliffs 

 of rock which may have been partly cut by glacial stream work 

 before the wave work by the lake. Examples of these cliffs may 

 be seen in North Collins; and east of the ridge road for 3 miles 

 south of Eden, and for a mile north of Eden. 



Strong channels in rock lie north, south and west of East 

 Eden. About a mile north of the village and just south of the 

 Lutheran church are two fine channels. West and northwest of 

 North Boston the slopes are cut ; and the conspicuous Whittlesey 

 cliff 2 miles southeast of Hamburg was probably made partly by 

 stream action. 



The detritus carried by the streams at North Collins was probably 

 swept into the Cattaraugus valley below Gowanda. The channels 



