4. _East St. Louis, St. Clair County._—Dr. F. V. Hayden (Proc. Acad. Nat. Sci. Phila., 1866, p. 316) announced the finding of a tooth of a mastodon in the bluffs opposite St. Louis. This was probably in St. Clair County.
In the American Museum of Natural History, New York, is a lower right last molar of a mastodon, labeled as having been found in St. Clair County, but there is no other information.
In the collection of the St. Louis Academy of Science there are two teeth of a mastodon, right and left last upper molars, which had been brought in by a boy and presented to the Academy. He said that they had been found in East St. Louis and had been in the possession of the family for some time. The length of the left molar is 175 mm., the width 102 mm. While the valley of the Mississippi River is here filled by deposits laid down during the Wisconsin stage (Leverett, op cit., plate VI) and by later-formed alluvium, Illinoian drift enters into the bluffs, and perhaps pre-Illinoian interglacial soils. It is, therefore, of interest that there should be an exact record made of the place of discovery of every bone and tooth found, the character of the deposit, and the depth of burial. In all the cases here recorded no such records have been kept.
5. _Alton, Madison County._—In 1866 (Geol. Surv. Illinois, vol. I, p. 315; 1871, Amer. Naturalist, vol. V, p. 607), A. H. Worthen reported that a part of a jawbone of a mastodon, with two teeth in it, had been found in the lower part of the loess, 30 feet below the surface, at some point just above Alton. The jaw was separated from the limestone by 2 or 3 feet of local drift. The bone was of a chalky whiteness and in a fine state of preservation. Worthen wrote that the loess on the bluffs in this region is from 40 to 80 feet in thickness, but appears in places to have been removed by erosion, so that it comes down to the rock.
Reference is made by Worthen later (Geol. Surv. Illinois, vol. VIII, p. 8) to the discoveries of vertebrate fossils in the drift and loess of this region. He mentions that Hon. William McAdams found, at Alton and Chester, remains of mastodon, mammoth, megalonyx, castoroides, and “_Bos primigenius_.” McAdams’s collection is now in the U. S. National Museum and a list of the species is presented on page 339. These species were described by the writer in 1920 (Proc. U. S. Nat. Mus., vol. LVIII, pp. 109–117). In it are only two fragments of molars of this species.