W. Md, Fontaine— Mesozoic Strata of Virginia. 233 
Belt, show glacial strize, but some of them show a mode of wear 
and polish highly suggestive of ice action. Indeed it is not 
robable that these fragments would show striations even if they 
ad been imbedded in ice moving over the land, for the surface 
was no doubt too deeply decayed, and in too incoherent a con- 
dition to produce scratches. 
Besides the Potsdam, we find other material which has been 
brought from west of the Blue Ridge. Slabs of the character- 
beautifully preserved. They consist of Conifers, Ferns and 
yeads. The Conifers sometimes retain their cones. They be- 
long to several species, among whi on a plant 
Mesozoic crops out from under the Tertiary, we find the Pots- 
dam stones, Azoic erratics, fragments of Mesozoic sandstones, 
