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south to the South Fork of Donaldson Creek, whence it bears southwest, passing along the south side of the creek valley and crossing Sulphur Creek about 2 miles below the town. From the point of crossing on Sulphur Creek it occurs along the hillsides east, north, and west of Lampasas. The Basement beds at this locality are apparently the margins of the lower portion of the Glen Rose formation, surrounding a local projection in the Paleozoic floor.

In the Central Province, between the western border of the Grand Prairie in Comanche County and the eastern border of the Llano Estacado, are many remnantal areas of the Basement sands spreading out from the foot of the table-lands and buttes of the Callahan Divide and overlapping the edges of the lower-lying plains. These " sandroughs," as they are locally termed, rest upon Carboniferous and Permian rocks. They stretch westward irregularly from northern Brown County along the southern side and between the various buttes of the Callahan Divide and in a northerly direction along their northern side from the northwestern portion of Comanche County across southern Eastland, northern Brown, and southeastern Callahan counties. The sand extends fully 200 square miles in the more western counties and is of the age of the Paluxy formation, the Glen Rose limestone no longer appearing.

It has already been shown that the Comanche sea at the close of the Trinity epoch had overcome the old Paleozoic barrier beneath the Grand Prairie, and how during the succeeding Fredericksburg epoch it swept gradually west and north over the vast areas of the Central and Plains provinces, reaching southern Kansas and northwestern New Mexico at its close. During the Fredericksburg subepoch the Cretaceous shore reached west and north approximately to a line extending from El Paso north into southwestern Kansas. The area lying south and east of this line, as far at least as the eastern border of the Black Prairie, as shown by the extent of the Edwards limestone, was a great arm of the sea, the bottom of which was covered with calcareous organisms as certain banks of the present West Indian seas are now covered. Over the entire area thus covered by the oceanic waters the sea deposited a mantle of arenaceous, argillaceous, and chalky sediments which now make the rocks of the Fredericksburg division. Not only were the sediments thus deposited over a far greater area than that previously occupied by the Trinity seas, but they were also laid down over the sediments deposited during the Trinity epoch. Hence, these rock