12. _Hickory, Washington County._—In 1875, Professor J. J. Stevenson (2d Geol. Surv. Pennsylvania, K, p. 22) reported that a mastodon tooth had been found in Mount Pleasant Township, in the county named. It was said to have been discovered on the high divide between Raccoon and Chartiers Creeks. The tooth is preserved at Washington and Jefferson College, at Washington, in the county of the same name. Professor Edwin Linton has informed the writer that the tooth was found about 1 or 1.5 miles southeast of Hickory. This indicates that it was found along Westland Run, probably about halfway down to the village of Westland. The geological position and possible age will be discussed on page 323. 13. _Erie, Erie County._—In the Erie Public Museum the writer has seen a part of a lower right hindermost molar of a mastodon which is labeled as having been found long ago on what was called Frontier farm, about 2 miles west of the Public Library, below Eighth street and toward the lake. The discovery is credited to W. F. Leutzer. The locality would apparently be on Chase Creek, at an elevation of about 600 feet above sea-level, unless it had possibly been buried along the creek in some pre-Wisconsin formation. In lack of the information that ought to have been preserved it may be impossible to arrive at any certain conclusion. Mr. Clyde C. Hill, civil engineer, North East, Erie County, has informed the writer that Chase Creek flows through the old Frontier farm. OHIO. (Maps 5, 7.) IN UNGLACIATED REGION. 1. _Pike County._—In 1875 (Cincinnati Quart. Jour. Sci., vol. II, p. 154), J. H. Klippart wrote that the upper jaw of a mastodon, with a considerable part of the cranium, had been found somewhere in this county and had been on exhibition in the State Agricultural rooms. It was owned by a Mr. Faust, of Galion or Crestline. Nothing more appears to be known about this specimen. 2. _Nashport, Muskingum County._—In 1837 (Amer. Jour. Sci., vol. XXXI, p. 79), S. P. Hildreth, in an unsigned article, stated that mastodon remains had been found 2 miles north of this place, during the excavation of a canal. He recognized large portions of tusks and some molar teeth. At the same place were found the skull which became the type of _Castoroides ohioensis_, as well as a skull which Hildreth described and named _Ovis mamillaris_, but which probably belonged to a domestic sheep.