ILLINOIS.
1. Galena, Jo Daviess County.—In 1848, Dr. John L. Le Conte (Amer. Jour. Sci., vol. V, pp. 102–106) described what he regarded as 5 new species of fossil mammals from the lead region of Illinois. These had been secured by Mr. Wm. Snyder, of Galena, in a lead crevice 50 feet below the surface, filled with a mixture of clay and sand cemented by oxide of iron into a hard mass from which the specimens could not be removed without great injury. The species described were called Platygonus compressus, Hyops depressifrons, Protochœrus prismaticus, Procyon priscus, and Anomodon snyderi. The last was regarded as related to the moles. Procyon priscus resembled closely the existing P. lotor. The 3 species first mentioned are now regarded as belonging to a single species, which takes the name Platygonus compressus. It may be remarked that the original spelling of the generic name was due perhaps to a lapsus calami or to a printer’s error. In the complete paper published shortly afterward the name was spelled Platygonus. It is to be added that the teeth which served as the type of the so-called species Protochœrus prismaticus were found at a locality 15 miles from the place where the other remains were obtained; but as to where this place was nothing is said.
In 1848 (Mem. Amer. Acad. Arts, Sci., vol. III, pp. 257–274, plates I to IV) Platygonus compressus was more completely described. Various teeth and parts of the skull and some limb-bones were figured. In this article it is stated that the remains described had been found in a lead crevice a few miles from Galena. A portion of the bones had been preserved by the miners and had at length found their way into the hands of Mr. Snyder, a merchant in Galena.
In 1852 (Proc. Acad. Nat. Sci. Phila., vol. VI, pp. 3–5) Hyops depressifrons and Protochœrus prismaticus were further described, the first being placed in the genus Dicotyles. Both of these are now regarded as belonging to Platygonus compressus.
The writer has considered it as probable that the peccary remains, as well as Procyon priscus and Anomodon snyderi, are of Late Wisconsin age; but it is possible that they are somewhat older. The reader is referred to page 343, where the Pleistocene of the lead region is discussed.
2. Alton, Madison County.—In the McAdams collection, of which a general account has been given on page [339], is a part of a lower canine tooth which apparently differs in no way from the corresponding canine of Platygonus cumberlandensis, found by Mr. J. W. Gidley in a limestone fissure near Cumberland, Maryland. On page [350] will be found a list of the species found in this fissure and their geological age.