An Account of the Middle Silurian Rocks of Ohio and Indiana. 



169 



5. Sharpsville. — This section is described in the paper on Clinton 

 conglomerates, above mentioned. The total thickness of the Clinton 

 is about twenty-seven or thirty feet, judging by means of the barometer. 

 The lowest pebble was found a short distance east of the entrance of 

 the small stream from the Alexander farm into the creek, at an eleva- 

 tion of about 14 feet above the base of the Clinton. The pebble 

 measured 20 by 9 inches; it was a piece of chert such as is found in 

 the basal Clinton, and contained Calymene vogdesi, Phacops trisulcatus a 

 pygidium with 4 lateral pleurae, OrtJiis (Platy strop Jiia) biforata, large 

 form, OrtJiis [Dalmanella) elegantula, and Rhynchonella acinus, var. 

 tonvexa. The bedding of the Clinton is strongly marked here and 

 also farther up the creek, but it is uneven. Good pebbles, 4 by i}4 by 

 3 inches are found farther up the creek, about 18 feet above the base of 

 the Clinton. The pebbles here were composed of the bluer, finer 

 grained Clinton. Going northward up the small stream the bedded 

 Clinton is found 1 1 feet above the base of the Clinton, and the Clinton 

 conglomerate is found 18 feet above the base of the Clinton. The 

 Clinton conglomerate at the east and west fence is found about six to 

 8 feet higher up. The upper Clinton at this point does not show 

 pebbles, being reddish crinoidal, turning at the top into a dark red 

 sandy rock containing Rhynchonella acinus var. convexa. This fossil 

 is shown for instance along the west side of the stream just south of 

 the line of barns on the Sharp farm. The thickness of the Belfast bed 

 in the creek bed opposite Sharpsville is about 4 feet. In addition to 

 annelid teeth, a species of OrtJiis, a little on type of Orthis calligramma, 

 with 44 plications, was found. The barometer reading placed the top 

 of the Clinton at the creek exposure southeast of Farmer's Station at a 

 level about 15 feet below that at Alexander's quarry in the Sharps- 

 ville section. 



6. Todd's Fork. — Where the Xenia pike crosses Todd's Fork, 

 about three miles north of Wilmington, the base of the Dayton lime- 

 stone is well exposed. Underneath lies the more or less ferruginous 

 Clinton. A deeply red layer with small oolitic iron grains occurs 

 about 5 feet below the Dayton stone, and contains a new species of 

 Craniella. The pebbles found almost opposite the Miar house farther 

 down stream occur about 10 feet below the Dayton limestone. The 

 total thickness of the Clinton is about 35 feet. The Belfast bed here 

 has a thickness of 5 feet, and contains annelid teeth. About two feet 



