Marathon, Texas, March 16 - 1924 Sunday. Walked most along Southern Pacific R.R. to culture 579 A, about 3 1/2 miles north of Marathon. Here is a very small exposure in white silt with the shales dipping steeply to the east, about 55 degrees. It is a greenish sandy shale with gritty sandstones, the latter in thin beds fine 1/2 inch to one foot thick. Some surfaces are replete with small pieces of coral, all casts showing very original fibrous condition. There are slightly semi-crumbled, and there are some very small angular conglomerates. Saw a few thin sandy impure limestones and those had a few crinoid stems and fragments of Fucostella. One of the sandstones are cast-in-folds (pulvatoites) trees. Go down descending toward an anticline there shall be the first shales or siltstone layer. Sand clay in the Unogronian, Just west of culture 579 A more of the same coral [fragments] in exposed. Here the casts traces are common. The sandstone layers are craggier, and conglomerate pebbles, up to 3 inch across, are