6. _Dayton, Montgomery County._—In 1820 (Amer. Jour. Sci., ser. I, vol. II, p. 245), Caleb Atwater wrote that teeth of the mastodon had been found at Dayton. No details were given and the case is not illuminating. The weights given for some of the teeth make it doubtful whether or not he distinguished mastodon teeth from those of elephants. About the first of April 1921, Mr. C. E. Pickering, of Lake View, Ohio, sent to the Smithsonian Institution for identification a well-preserved upper right second molar of a mastodon. This had been found 4 miles east of Dayton in an excavation, 30 feet below the surface. The tooth is 130 mm. long and 95 mm. wide. The surfaces of the cones are furnished with welt-like ridges which descend from the summit to the bases. This whole region is occupied by Wisconsin drift. It is probable that the tooth was found in some river deposit, not in the drift itself. 7. _New Paris, Preble County._—Professor Joseph Moore (Proc. Ind. Acad. Sci. for 1886, p. 277) reported that many bones of a mastodon had been discovered by a farmer living 2 or 3 miles from New Paris. Two grinding teeth and one tusk nearly 11 feet long were part of the remains. The bones became the property of Earlham College. Nothing was said regarding the circumstances of the discovery, but the bones were probably found in one of the marshes so common in that region. New Paris itself appears to be situated on the Germantown moraine. 8. _West Sonora, Preble County._—In 1893 (Amer. Geologist, vol. XII, p. 73) Professor Joseph Moore reported that mastodon remains had been found near Sonora, Preble County, in company with a fragment of a tooth of _Castoroides_. He probably meant West Sonora, as there is, at present at least, no town by the name of Sonora in the county. He furnished no details as to topography or geology. West Sonora is on the Englewood glacial moraine. 9. _New Madison, Darke County._—The museum connected with the public library in Greenville, Darke County, contains a large lower jaw of a mastodon with the second and third molars, right and left, found near the headwaters of Mud Creek, on the farm of Elias Harter. The place was evidently near the village of New Madison. The township is number 10 north, range 1 east, and is named Harrison. In the same collection is a part, about 4 feet long, of a tusk found on the farm of Daniel Ruh, about 2 miles north of New Madison. It was met with at a depth of 3 feet in digging a ditch. For the geology of the region see page 326. New Madison is on the Englewood moraine. 10. _Fort Jefferson, Darke County._—In the collection at the public library in Greenville is a nearly complete mounted skeleton of a mastodon found about 1908, in Neave Township, 11 north, range 2 east, near the village named. The spot is on the Delaplaine farm and near the headwaters of Bridge Creek. The region is very flat and was originally swampy.