pt. II., cont'd. book VIII. Eighth Palaeozoic district, or anthracite coal-basins, and encircling belts of the older Carboniferous rocks. book IX. Ninth Palaeozoic district, or bituminous coal-fields and their associated older Carboniferous strata. pt. III. Mesozoic red sandstone series. pt. IV. Igneous rocks and minerals, veins and ores
Geological Survey of Pennsylvania