Trans. N. Y. Ac. Sct. 84 _ fan. 9; 
that the most delicate marine organisms are beautifully preserved. In 
places the Trenton limestones abut directly against the Laurentian 
clitts which formed the shore, and which suffered so little wear that 
they contributed scarcely anything to the organic sediment deposited at 
their base. This record hardly requires translation to be understood 
by all, and its antagonism to the proposed theory is apparent and irre- 
concilable. 
Toward the close of the Lower Silurian age, the sea slowly retreated 
from the land it had before invaded, forming wide areas of shallow 
water in which grew countless numbers of sea-weeds and delicate 
graptolites, the carbonaceous matter of which, mingling with a fine 
wash from the land, produced the bituminous clays which we now call 
the Utica slate. It is evident that the organisms which supplied the 
combustible matter of this deposit could only have lived in quiet lagoon- 
like bays, and their presence and product, with the fineness of the inor- 
ganic sediment, are incompatible with Prof. Ball’s theory. 
Similar phenomena teach the same lesson in the records of the Devon- 
ian, Carboniferous, and later geological ages. In the Devonian rocks 
we have another and apparently conclusive argument against extraor- 
dinarily high tides, for here are coral reefs, rivaling in extent those of 
the tropics at the present day. Now unless the reef-building polyps 
were formerly altogether different in habit from those now living, these 
coral reefs must have been formed in water not exceeding two hundred 
feet of average depth and not subject to great oscillations of level. 
High tides would now effect the rapid destruction of the whole race 
of reef-buildirg animals ; at the ebb exposing them to the air and sun 
for hours, and at the fiood burying them too deeply for their continued 
existence. 
The abundant sea-weeds buried in the rocks of the Paleozoic and 
later ages, offer an equally strong argument against the high-tide theory. 
Nearly all the sea-weeds now living in our oceans occupy the immediate 
shore, and chiefly grow within a depth of from 50 to I00 feet from high- 
water mark. It is easy to see that if the present oceans were affected 
by a movement like that described by Prof. Ball, the zone the sea-weeds. 
occupy would be the scene of the greatest mechanical violence, and 
they would be alternately left to dry in the sun, or be torn with resistless 
force from their anchorage and scattered over the, land washed by the 
flood tide. On every old beach, however, of which we find so many in 
the geological series, the casts of the fronds and stems of sea-weeds 
are as plainly discernible as on our present shores. 
In view of these facts, and others of similar import which might be 
cited, we are compelled to reject this theory of high tides, at least for 
the interval which separates us from the beginning of the Laurentian 
