above sandstone member 44 ft. -Thin bedded fine grained, hard sandstone 16 ft. Left the section of the main escarpment to be finished by Dodds, upon arrival of Crawford, Underhill and Jackson. We all visited the gypsum beds together. After lunch Crawford, Robbins and Dodds continued measurements of the Carboniferous section, while Underhill, Jackson and I examined the Chugwater and Jurassic. After Underhill, Crawford and Jackson left at 4 p.m. Robbins and I went down to the Niobrara formation on horseback. Found the basal limestone not so massive as at Boulder, containing Inoceramus deformis, Ostrea congesta and an Ostrea and an Inoceramus new to me. It is underlaid by 3 or 4 ft. of sandstone, below which is the Benton shale. The Niobrara here divides into two high ridges with a minor one and another still lower in between. In the latter 3 are Ostrea congesta on an unknown large
