38 BULLETIN OF THE 



to the n^ve only of any local glaciers which might have formed in the 

 north- and south-sloping valleys on each side of the " cols." 



An amount of chloritic schist vastly greater than is represented by 

 the trains may have been removed by the ice from the crest of the 

 Canaan and Lebanon Range, but all, except the boulders of the trains, 

 has been more or less ground to pieces in the glacial mill, and is now 

 imbedded in that formation which has been the ground moraine of one 

 or more general ice-sheets. 



The facts connected with the Richmond Boulder Trains thi'ow little, 

 if any, additional light on the explanation of glacial phenomena in 

 general, but the theory' of a general ice-sheet, as it is received by most 

 geologists, seems competent to explain, in considerable detail, not only 

 the origin, but most of the marked peculiarities of the trains, and in so 

 far as it does this, it receives fresh confirmation from the facts which 

 have been stated. 



