421 
Geology . 
deposits would gradually be made from the waters, now 
decreased in quantity; and take their place below the 
summits of the primitive range. Those summits being 
exposed to the action of the atmosphere, of rains, of frost 
probably, and to the action also of the waters with their 
contents still incumbent on the earliest strata, would fur- 
nish masses and particles washed away, which would 
mingle with the deposits of the transition series : this se- 
ries therefore, will exhibit appearances of mechanical and 
chemical intermixture of earths and stones such as are 
found in the green stone, siliceous hornblende rock, argil- 
laceous hornblende rock, grau wacky, and lastly, wacky 
which form the trap rocks of the transition series. Spe» 
cimens of these trap formations can be traced from Perkio- 
men Bridge, through Reading to the mountain ranges of 
shistus that reach from Putt’s forge to Sunbury, in Penn- 
sylvania. The transition limestone is the earliest of this 
series, but I have not had occasion to remark the flint 
slate or the transition gypsum. During the period when 
these transition formations were deposited, there would be 
no land animals, for there would be no vegetables for 
them to feed upon. There would be no vegetables, un- 
less some few lichens, mosses, or ericas, that would find 
foothold upon the slight decomposition that after the lapse 
of some ages would take place on the surface of the pri- 
mitive rocks. The sea only would be peopled, and that 
but sparingly ; for in that mass of muddy water, none 
but the lowest and most inferior grades of animal life, 
and such as do not inhabit deep water could exist. Hence 
we find the transition formations contain in their sub- 
stances, some belemnites, asterise, entrochi, echini, &c. 
but no organized vegetable substance except very rarely 
in the latest rocks of this series, and no remains whatever 
of terrestrial animals. 
