Archeater shale. The horizon at which the fossils come in along with the fine lymne slate is about 20 feet below the Trenton limestone. This zone is about 3 feet thick, in which the thin lie around. They occur both in thinnings and wider separating lines. known all the way below to the Clinton limestone or that the prolificuous Archeater shale embraces all of the lower 20 fathoms. Clinton limestone. The change from the Archeater shale to the solid, hard and highly prolificuous limestone usually occuring in 1 to 2 inches, just as we can see at Brinny. Then below the Clinton li. is famous prolificous. The species are those of the Archeater shale except that I did not see D. micfarsonii. The lower bed of Clinton has a tendency in the upper 30 inches of splitting up into beds, thinner beds, but in reality does does not. There are zones of stylolites and small cavities thickens about 8 to 10 feet. Below are thinner bedded greish magnesian limestone in beds 2 to 14 inches but in general 4 to 6 more, those appear the derived of fossils, thickness 8 to 9 feet. Below are once thin beds, many in definition, about