with shale chobs at the top, about 15 feet thick. A. harlani en- tirely occurs in the upper 3 feet and may go lower. Much sun-cracking at least in the upper 2 feet. Then come dark ledged sandstone, with less dominant shale partings, the sandstone considerably channelled and all muddled into A. archimedes. These beds are all mottled with green solution or alteration spots. About 15 feet. Grey Band grit over 4 feet thick. Therefore the Medina is at least 50 feet thick. These thicknesses are estimates. Look at contact. In the large quarry on North Goodman Street one sees a fine contact between the Archeton shale (here quarried for building stone) and about 1 foot of base Locketh. The top of the Archeton is nearly irregular to the extent of at least 4 feet. Over it follows a muddy deformed layer about 2 to 3 feet, all