Mineralogy and Geology. 123 
Foliation has also been noticed in the baked rocks of Salisbury Crags. 
Prof. Forbes concluded, 1, that foliation was a superinduced structure ; 
2, that it was distinct from cleavage ; 3, that it was not of mechanical 
origin, but a chemical phenomenon ; 4, that it was, perhaps, induced by 
more than one agency. , 
5. On the Relations of the “ New Red Sandstone’’ of ithe Connecti- 
cut Valley and the Coal-bearing rocks of Eastern Virginia and North 
Carolina; by Prof. W. B. Rogers, (Proc. Boston Soc. Nat. Hist., 
1854, p. 14.)—Prof. W. B. Rogers exhibited a series of fossils from 
the middle secondary belts of North Carolina, Virginia, Pennsylvania, 
and Massachusetts; chiefly, he said, with the view of calling attention 
to the evidence afforded by some of them, of the close relation in geo- 
logical age between what has been called the New Red Sandstone of 
the Middle States and Connecticut Valley, first designated by Prof. 
D. Rogers as the Middle Secondary Group, and the coal-bearing rocks 
of Eastern Virginia and North Carolina. : 
rof. Rogers referred to the existence in Virginia of three distinct belts 
of these rocks. e most eastern of these, extending almost continu- 
ously from the Appomatox River to the Potomac, includes the coal- 
fields of Chesterfield and Henrico Counties. The middle tract, about 
ing southwestwardly across the State, and for a few miles beyond its 
limits, into South Carolina. This area, first mapped by Prof. Mitchell, 
includes the coal-bearing rocks of Deep River. The western belt ex- 
tends, with two considerable interruptions, entirely across Virginia, be- 
