WARREN COUNTY. 383 
most division, viz., the Lebanon beds. Besides this, it contains from 125 
to 150 feet of the upper beds of the middle division, or the Cincinnati 
beds, proper. These strata have dipped from a height of 450 feet at Cin- 
cinnati, to that of 275 feet at Lebanon, an average fall of about six feet 
to the mile to the northward, a result which is, in the main, harmonious 
' with the general facts already established in regard to the dip of the 
Blue Limestone beds. 
The Cincinnati rocks furnish the floor of Warren county, as of South- 
ern Ohio generally. Indeed, they constitute almost the entire surface of 
the county, the Cliff Limestone not occupying more than ten square miles 
of its area. The accompanying map indicates the outliers of the Cliff 
Limestone and also the boundaries of the main valleys of the county. 
No detailed description of the strata of the Blue Limestone of Warren 
county is necessary. All the typical peculiarities of this division of 
rocks are shown here. As a consequence, the county is abundantly sup- 
pled with an excellent quality of building-stone, which can also be 
burned into lime fit for coarse work and for agricultural purposes. Unex- 
ampled displays of the strata, especially of the upper division, are fur- 
nished by the many tributaries of the Little Miami, so that every foot 
of the vertical ascent can be studied in hundreds of exposures. As a 
consequence, the fossils of the system are here displayed in their greatest 
perfection. They occur in such numbers and in such striking and well- 
preserved forms, that they can not fail to attract the notice of even care- 
less observers. It is hardly necessary to name particular localities in 
this connection, when every branch, if followed back from the river to 
its sources, reveals these beautiful forms in wonderful profusion. A sec- 
tion exposed on the old Lebanon and Wilmington road, just after it 
crosses the Little Miami River, in passing eastward, deserves mention, 
however, because of its unusual extent. It shows ina very steep ascent, 
about two hundred feet, mainly of the Lebanon beds, beginning with 
that stratum of Orthis biforata, which is taken as the summit of the Cin- 
cinnati section proper. This locality is one of the best known for the 
occurrence of the interesting form Orthis retrorsa, Salter, which comes in 
at forty to fifty feet above the Orthis biforata bed. It has no monopoly of 
this fossil, however, as the shell occurs in every section between Morrow 
and Cesar’s Creek that exposes its particular stratum. This locality is 
of special interest, also, because it yielded the typical specimen of a new 
crinoid—the Heterocrinus jwvents of Hall. 
A very interesting section is furnished by Longstreth’s Branch, oppo- 
site Freeport, which deserves special notice, also, on account of having 
given several new fossils to science, among them two crinoids—Glypto- 
