564 A. F. FOERSTE 



dense limestone, 6 inches thick, the fossils not readily recog- 

 nizable ; and reddish clay, 20 inches thick, containing most of 

 the fossils collected. 



Along Horse Creek no exposures of Richmond limestone or 

 Mannie clay have been found, although a single specimen of 

 Rhynchotrema capax manniensis was collected in the very thin layer 

 of residual clay intervening between the Saltillo limestone and 

 the Silurian at Maddox mill. The Saltillo limestone is exposed 

 for more than a mile along Willoughby Creek, at the old Lick 

 Ford, near its mouth, and at the Maddox mill. At the mill the 

 lower part of the Silurian, 2 to 7 feet thick, is hard and cherty, 

 and is referred to the Clinton. Above it is massive limestone, 

 23 feet thick, bluish near the base, white throughout the rest of 

 the section. This massive limestone corresponds stratigraphically 

 to the white limestone section, 18 feet thick, which overlies the 

 layer of chertat Swallow Bluff. The Osgood, Laurel, and Waldron 

 beds have, so far, not been identified along Horse Creek. No 

 exposures have been found at the proper horizons. 



At the home of W. D. Helton, about 35^ miles northwest of 

 Waynesboro, on Beech Creek, the Saltillo limestone is well 

 exposed. The Richmond limestone, 7 feet thick, is seen several 

 hundred yards up stream, on the south side of the creek. The 

 Mannie clay is probably 20 to 25 feet thick. The base of the 

 Silurian section forms a cliff on the north side of the creek, about 

 100 yards farther up stream. The Mannie clay beneath the 

 cliff is weathered back, and immediately above there is almost a 

 foot of ferruginous material, very much weathered, which may 

 represent the ferruginous chert at the base of the Silurian in 

 other sections. Immediately above is massive limestone, 6^ 

 feet thick; followed by massive, bedded limestone, 8^ feet 

 thick; and well-bedded limestone, 12^ feet thick; a total of 

 27^ feet corresponding stratigraphically to the Silurian lime- 

 stone exposed at the Maddox mill. Immediatelely above, for a 

 distance of 10 feet, there is no exposure. The total thickness 

 of the Silurian section at the W. D. Helton locality is 104 feet. 

 A careful search along the bluffs lining the creek will, no doubt, 

 reveal the position of the Waldron bed. Until this has been 



