54 
MUSEUM BULLETIN NO, 25. 
shore line, or, if it was only shallow water control, to the con- 
tours on the sea floor. . . .This shore line or the contour of the 
bottom must have been parallel to the ripple direction, that is, 
it must have extended in a northwest southeast direction." 
Hyde’s conclusions regarding the trend of the shore-line seem 
unassailable from the evidence of the ripple-mark presented. 
But no direct evidence as to whether the shore-line was east or 
west from the area studied can be derived from the ripple-mark. 
Prof. Hyde’s conclusions that the Berea shore-line lay to the 
southward is based upon other considerations than the ripple- 
mark evidence. In this conclusion I do not concur, but this 
point is not material to the present discussion and need not be 
pursued here. 
ORDER OF SUCCESSION INDICATED BY RIPPLE-MARK. 
In areas of excessive orogenic disturbances it is often very 
difficult to ascertain with certainty the original order of super- 
position of the beds. The discovery in such beds of ripple-mark 
often serves to clearly indicate which is the top and which is the 
bottom of the section. A reversed or overturned bed of ripple- 
mark would, of course, indicate a corresponding reversal of the 
original order of the beds of the section. This use of ripple-mark 
in determining order of superposition, of course, assumes that the 
trough and crest in ripple-mark are unlike and distinguishable. 
Certain kinds of ripple-mark which have ridges and troughs 
distinctly unlike may be used in this way. Where the crest and 
trough show a similar degree of curvature as in the case of some 
wave-made ripple-mark it would be impossible to distinguish the 
sandstone mould from the original ripple-mark. Most examples 
of current made ripple-mark exhibit the same characteristic, 
the contour of the trough and crest being so nearly identical that 
discrimination between a mould and the original would be very 
difficult and often impossible in the case of fossil ripple-mark in 
beds where the order of superposition was unknown. This will 
be clearly seen by reference to the ripple-mark profiles in Figures 
3 and 7 H and I. If the top and bottom of figures 3 E and 
3 F or 7 H and 7 I be reversed the figures will show nearly the same 
