case as in the next zone below. Actual thickness 4 feet. (13) Redden bedded dolomitic limestones. Actual thickness 17 inches (14) Blue-green coalescent shale seen in bluff facing rail- way bridge. Actual thickness 8 feet. (15) Transition shales to red-brick-red beds below. These are blue-green beds with the grain of the brick red. Actual thickness 23" (16) Brick-red shales to above yard and in Dominion Oil- Plant Railroad cut. Thickness unknown but considerable. May be at least 75 feet thick. As the tide was completely out at noon watched up the shore of the Crock at low-tide line and one sees better here than at high-tide line the general structure. Just where on top the gypsum occurs there is another pitch diamond followed by a great mass of red beds with some harder dolomitic rough horizontal dolomite grain before the Millers quarry zone is reached. The Chagres Point horizon must be still higher followed by the second thick of gypsum on top of it. The entire thickness of the Prindon series is considerable, much greater than my original estimate of 240 feet. It will run near 600 to 800 feet. Most of the material in shale and probably one-half of the entire is red shale. To the west of the railroad bridge end of the Crock the beds show considerable difference of strike and particular dip. There are several smaller faults but none of these I interpret as broken arches or rolls in the crumpled beds. The own thrusting and faulting is to N.N.E.