The Ciueinndii Rodi.r — l\'riii. 321) 
interpreted as trails of annelids, tnoilusks, etc., and the im- 
pressions of fucoids. Still further examination has disclosed 
markings such as might be made by trickling water, others 
that look like mudcracks. and so on. 
These have been more particularly noticed in the vicinity 
of the wave-mark horizons, and have led Shaler of Kentuck}^ 
and Prof. Jos. F. Janies, to the conclusion that they indicate 
ancient beach-marks. The latter, in a paper which appeared 
in "Science," March 20, 1885, vol. v. p. 231 et seq., speaks of 
all of these, and concludes that there are at least two well 
defined beaches and probably others not yet discovered. To 
account for these he assumes as many alternate upheavals 
and depressions of the ancient sea bottom, but says nothing 
to imply that he does not believe the general coiulition of the 
sea to have been a deep one. To substantiate his oi)inion of 
the littoral character of these two or more horizons, he gath- 
ers together many evidences not before published, I believe, 
and sustains his argument in a masterly and convincing 
manner. 
My own attention was especially called t»j the study of the 
ph^'^sical history of these rocks three summers ago when I 
found in an exposure on the Four Mile creek, near Oxford, 
Butler county, 0., a slab about fourteen inches in length by 
nine inches broad, beautifully covered on one side with unmis- 
takable rain-drop impressions. ( Fig.l)This slab Avas of limestone 
of the average grade of purity found throughout the Cincinnati 
group, and was an exceedingly interesting specimen. Both 
above it and below it were strata bearing the ''dumb-bell" fos- 
sil, and filled witli trails and other markings, all of which 
seemed indicative of littoral conditions. But to make the 
conclusion positive it seemed necessary that other concurrent 
testimony be adduced, such as wave-marks, rill-marks, mud- 
cracks, etc., and I have devoted myself at intervals ever since 
to collecting such evidence. 
Dr. F. W. McFarland, then president of Miami University, 
upon seeing the specimen, at once recognized its value and 
importance, and most kindly volunteered to run a line of 
levels from some established bench-mark to the horizon from 
whence the rock came. Previous to this the village of Oxford 
had sunk an unsuccessful gas- well near the C. H. A: I. depot 
which had given us a complete geological section from near 
