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found occasionally in great masses. Accompanying these beds are also many new and undescribed species.

The chalky deposit of the Caprina limestone is no doubt the continuation and culmination of the great Lower Cretaceous subsidence, and will be of great service in future interpretation and final correlation. It is very uniform, and covers large areas of the Grand Prairie plateau in southwest Texas, especially in the region adjacent to the lower Pecos. It also caps the mesas of the remnantal areas in the Abilene country, and as far east as Comanche Peak in Hood County. The railroad from Brueggerhoff to McNeil along the Williamson-Travis County line crosses a typical portion of its strike.

At Austin a fault of about 750 feet downthrow has broken this limestone division into two different areas, and hitherto confused its measurement.

The Caprina chalky limestones which mark the culmination of subsidence in the Comanche series are succeeded by deposits of a lithologic and stratigraphic character which indicate that the ocean's bottom had reached the culmination of the long subsidence which it had been undergoing since the beginning of the Trinity beds, and had commenced the gradual elevation which finally terminated in the Mid-Cretaceous land. This shallowing is well illustrated in the rocks above the Caprina limestone, to which the name Washita Division has been given after the region where its rocks were first seen by early explorers near Fort Washita, I. T.

The Washita Division along the Colorado is composed of the following well marked subdivisions:

Of these horizons only the Washita limestone and the Exogyra arietina clays are known to have any persistent extent, these being found as far north as the Arkansas-Choctaw line and southwest to the Pecos.

THE FLAGSTONES.—These can be seen at McDonald's brickyard, Johnson's quarry, Taylor's lime kiln, and other points immediately west of Austin. They consist of thin flagstones, of almost pure chalky limestone, varying from one to three inches in thickness, and are void of fossils.

The surfaces of the slabs, which are quarried for paving and building stone, are sometimes covered with the pentagonal markings usually attributed to mud cracks, and these are filled with soft yellow lime material. These