194 EI. JLOOIIMNAIL OU? EIZQILOG VY. 
Conclusions to be drawn from wave marks and pebbles —No one 
who is familiar with wave marks as made along long surf-beaten 
beaches of the ocean, can doubt for a moment the origin of the 
wave marks. Their unusual size will, however, attract attention 
even from one familiar with the work of the sea. Yet it must 
be remembered that we are familiar only with the wave marks 
left by the edge of the sea, where the force of the waters has 
been almost spent. It is readily conceivable that farther from 
the shore different results, at least as regards magnitude of wave 
marks, might be expected. It has always been a hope of the 
writer to, some time, be able to photograph the bottom of the 
sea after some great storm, along some exposed coast, with good 
sand bottom. This could readily be done by a camera prop- 
erly constructed, using electric light as a means of illumination. 
The magnitude of the wave marks here referred to would 
indicate free exposure to the sea, but would not determine much 
as to its depth. The writer does not know of large wave marks 
at great depths. On the contrary the largest he ever saw were 
at the mouth of Hampton river, in Massachusetts, considerably 
above low water mark. These fully equaled the wave marks of 
the Ohio rocks. 
As regards the pebbles, all the evidence in the case of those 
found in the upper Utica, in the ‘‘Upper Hudson” and in the 
Clinton is to the effect that they were derived from practically 
the same beds as those in which they are now found imbedded. 
To be more precise, their lithological character and the contained 
fossils are always those of rocks belonging to the same bed in 
which they are now found or at best only a few feet farther 
down, but not sufficiently beneath to suggest their origin from 
a separate paleontological horizon, even on the basis of the 
most careful classification. Evidently the waters were shallow 
enough to permit erosion. This may have occurred without 
actual elevation of the rock above sea level, but it is more 
natural to suppose that such elevation above sea level did take 
place, that the land. area was but slightly elevated and was 
soon again submerged, leaving the irregularly eroded surface a 
