RECESSIONAL ICE BORDERS IN BERKSHIRE, MASS. 353 



jriQ_ g_ — This map shows the scheme by which the moraine series in one valley is 

 correlated with that in another parallel or branching valley. This scheme, supple- 

 mented by the rule of interpolation between adjacent ice-tongues of the same halt, 

 forms the theoretical basis for the reconstruction of the several recessional ice-fronts, 

 as shown in the next map. Some of the best lines, which are traceable with substantial 

 continuity, are shown upon this map. Nos. 2, 6, 8, and I2 form the principal founda- 

 tion for the application of the scheme. The area of Lake Housatonic is represented 

 in order to show the contemporaneity of the Lenoxdale and Glendale ice-tongues. 



