24. _Aurora, Kane County._—H. M. Bannister, in 1870 (Geol. Surv. Illinois, vol. IV, p. 113) wrote as follows: “A portion of the remains of a mastodon, consisting of the tusks and several teeth, was obtained in excavating the track for the Chicago, Burlington, and Quincy Railroad near the city of Aurora, and are now preserved in the museum of Clark Seminary at that place.” These same remains were described by the geologist C. D. Wilbur (Trans. Ill. Nat. Hist. Soc., vol. I, p. 59, figs. 1 to 3). He stated that both tusks and seven teeth were found, all well preserved. The tusks were 10 feet long and 10 inches in diameter at the base; they were curved upward and considerably worn at the ends on the underside. Charles Whittlesey (Smithson. Contrib. Knowl., vol. XV, art. 3, p. 16) probably referred to these remains. He stated that they were found in a swamp. Probably one of these teeth was sent to Dr. J. C. Warren, of Boston, the author of “The _Mastodon giganteus_ of North America.” It is described in the second edition of this monograph, on page 76. In the Proceedings of the Boston Society of Natural History, volume IV, page 376, Warren described a tooth, probably the same, which had been found 40 miles west of Chicago, at a depth of 8 feet. He said it was the largest mastodon tooth then known. In Netta C. Anderson’s list, page 10, it is reported that in 1875 some mastodon remains were found about 8 miles southwest of Naperville, which is in Du Page County. The locality would be not far from the common meeting-point of Kane, Kendall, Will, and Du Page Counties; also probably within 8 miles of Aurora. The remains, whatever they were, were donated to the museum of Jennings Seminary, Aurora. In Netta C. Anderson’s list it is stated that teeth and a tusk of a mastodon were found, in 1853, by workmen extending the Burlington Railroad south of Aurora. They were in a swamp near Fox River, where the Burlington shops are situated. These remains, probably the same as those above described, were presented to Jennings Seminary. 25. _Batavia, Kane County._—This town is in Kane County, about 9 miles north of Aurora. In Netta C. Anderson’s list, on page 13, Dr. E. S. Riggs, of the Field Museum of Natural History, reported that, somewhere in this vicinity, in cutting a ditch to drain a marshy lake of about 200 acres, some leg-bones and vertebræ of mastodon were found in a sticky clay from about 5 to 7 feet from the surface. Dr. Riggs writes that along the same ditch he picked up a jaw of the existing species of elk and some bison bones. _Maple Park, Kane County._—Doctor Rufus M. Bagg recorded in 1909 (Bull. Univ. Ill., vol. VI, No. 17, p. 50, plate IV) the discovery of a large part of the skeleton of a mastodon. It was found at a depth of 6 feet. The exact location was not given.