In its type locality near Tully, in the central part of New York State, the Tully limestone has a thickness of about 23½ feet and rests conformably on the Upper Hamilton (Moscow) shales. The contact between the two is well shown in the cliff of Tinkers Falls, several miles east of Tully, and appears to be an absolutely gradational one. This is shown by the fact that the somewhat sandy shales of the Upper Moscow gradually become finer and more calcareous and beds of a more strongly limy character alternate with layers of more argillaceous material. Finally, the lime entirely replaces the clay and the impure Tully limestone is developed. The contact is thus a transitional one, and the Tully must be regarded as marking the passage of sedimentation without break from the Middle to the Upper Devonic. The faunas, too, partake of this transitional character, as is shown by . . .