ILLINOIS.

(Maps [28], [38].)

1. Shawneetown, Gallatin County.—In the collection of the Academy of Natural Science of Philadelphia are a part of one incisor, two molars, and two petrous bones which were many years ago obtained by a Dr. Feuchtwanger, from a well at a depth of 40 feet. These were mentioned by Le Conte in 1852 (Proc. Acad. Phila., vol. VI, p. 53). Leidy has figured the incisor (Holmes’s “Post-Pliocene Fossils of South Carolina,” 1860, plate XXII, fig. 5; Ann. Rep. Geol. Surv. Pennsylvania, 1887, plate II, fig. 10). Leverett (Monogr. U. S. Geol. Surv., vol. XXXVIII, p. 65) states that at Shawneetown a boring for gas and oil penetrated 112 feet of alluvial and other deposits before reaching rock. His map (plate VI) indicates that here the valley of the Ohio is composed of sand and gravel plains of Wisconsin age. Under the conditions it seems impossible to form any certain conclusions regarding the geological age of this specimen. It belongs possibly to the later half of the Pleistocene.

2. Alton, Madison County.—In the McAdams collection, described on page [338], is a part of a large upper incisor, in two pieces, of a specimen of Castoroides, with McAdams’s Nos. 209, 210, and a small fragment of another incisor. All three specimens are more or less enveloped in nodules of hard materials. In 1883 (Trans. St. Louis Acad. Sci., vol. IV, p. LXXX) McAdams stated that he had seen, both in true and modified drift, remains of rodents large and small, but one, an extinct beaver, was of monstrous size.

For conclusions as to the age of the fauna secured by McAdams see page [339].

3. Charleston, Coles County.—In 1867 (Proc. Acad. Nat. Sci. Phila., p. 97), Leidy briefly described a skull of Castoroides, sent to him for examination by Professor A. H. Worthen. It lacked both zygomatic arches and the incisor teeth. The length of the skull was 10.5 inches. This skull had been found by someone while he was plowing in a field near Charleston. The region about Charleston is covered by the Shelbyville lobe of the early Wisconsin drift. The animal must have lived at some time after the deposition of that drift.

4. Naperville, DuPage County.—H. M. Bannister (Geol. Surv. Illinois, vol. IV, p. 113) reported a skull and other parts of the skeleton of Castoroides, found by a farmer in a slough not far from Naperville. The skull went to Colonel Wood’s Museum in Chicago, and it was probably destroyed in the great fire of 1871. This animal quite certainly lived after the retirement of the Wisconsin ice-sheet.