July 22. Marble Head. I am now convinced that we have found the base of the Ordovician at mile post 401. If we could see the actual contact between the Beidmantown, and the Portoroe marbles they would more certainly be an angular unconformity has. In any event Marble Head and all the beds of the Humbler from mile post 401 are of Portogric age. Dunton for a time thought that the Portorgie marbles folded over again (and united with the Beidmantown making the two a continuous series, to me is an impossibility for these reasons. The Portorgic marbles are of two series and the first one is altogether too thick for the Beidmantown. Then there is nothing that I know of in the Ord. To fill up the place of the schist series a mile thick unless we say that the variegated series is the equivalent, or that over the second marble must be the equivalent of the first one and the structure quite different from what it appears. Dunton takes the view that all of the drifts are of Portorgic age, and that the variegated series rests on them. East of the red slate quarries there is a zone of them hidden in, and blue shales with zones of li., enyl. It appears to be the same li., enyl. seen yesterday to the east of Gurling. What the relations are to the red shales was not determined, the next day it was clear that they were headed and is therefore myself born in the north (Hoot and my sketch tunnel of this evening. They are looking up all animals for the Reid Railway Co. They report 13 feet of clean coal in the Ordov again (? South Branch). The total thickness of the bed is nearer 30 feet.