74 
AUG. F. FOERSTE 
ville quarry can be proved identical with those found in the 
Edgewood limestone, the affinity of these specimens from the 
lower argillaceous strata in the Centerville quarry appears to 
be nearer those of the Edgewood formation than those of any 
other formation so far described. Additional material is needed 
to confirm such a correlation. 
Back of a house on the west side of the road following Beasley 
fork southward from West Union, Ohio, there is an exposure of 
Belfast rock, beneath the typical Brassfield. The upper layer, 
1 foot thick, is the typical Belfast. Below this is more shaly 
rock, containing Enter olasma caUculum. About 4 feet beneath 
the typical Belfast there is a thin argillaceous rock layer con- 
taining the Rhynchonelloid here identified as Rhynchotreta the- 
besensis Foerste, and a form resembling Hormotoma trilineata, 
Foerste, but smaller in size. Prof. W. H. Shideler, who was the 
first to recognize the Silurian age of these strata, found also a 
small form of Whitfieldella at this horizon. 
Rhynchotrema thebesensis was found by Prof. Shideler also on 
the E. P. Smalley farm, about 2 miles south of Lawshe, in Adams 
county, where a small stream flows into Brush creek from the 
east. Here the Belfast bed is feet thick. 
At the Whippoorwill chapel, miles northeast of West 
Union, the typical massive Belfast bed contains Platystrophia 
daytonensis Foerste and several annulated specimens of Ortho- 
ceroids, possibly Dawsonoceras. In the overlying thin-bedded 
argillaceous strata the same species occur as are found in the 
immediately overlying part of the Brassfield limestone. These 
thin-bedded argillaceous strata at the base of the Brassfield 
limestone, and carrying a Brassfield fauna, are especially com- 
mon in the northwestern quarter of Adams county, Ohio, between 
Winchester, Graces Run, Seamon, and northward. 
These argillaceous strata carrying the Brassfield fauna, 
whether these strata be thin-bedded or thicker-bedded, are dis- 
tinct from the lower argillaceous strata carrying the fauna listed 
from the base of the Centerville quarry, the Beasley Fork 
locality, and the locality 2 miles south of Lawshe, on the E. 
P. Smalley farm. The former are clearly of Brassfield age. The 
