On Leverett’s glacial map of Indiana this region is represented as being occupied by sand and gravel deposits resulting from glacial drainage. The musk-ox must have lived after the foot of the glacier had withdrawn nearly to the end of Lake Michigan.
ILLINOIS.
(Map [25].)
1. Bondville, Champaign County.—In the collection of the University of Illinois, at Champaign, is the rear portion of the skull with the horn-cores of a specimen of Symbos cavifrons. It is reported as found on the farm of John Busey, southwest of Champaign and 4 miles from Bondville. Professor S. A. Forbes informed the writer that the locality is in section 31, township 19 north, range 8 east. No details are known regarding the conditions under which the skull was found. The region is occupied by the Champaign moraine and it was after the retirement of the ice from this moraine that the animal lived. It may, however, have been not long after that time.
2. Manito, Mason County.—Mr. John Wiedmer, of St. Louis, presented to the U. S. National Museum (No. 7800) the rear half of the skull of a specimen of Symbos cavifrons found near Manito, at a depth of 5 feet, by workmen who were cutting out peat. A tooth of a mastodon, Mammut americanum, sent with the skull, is said to have been embedded in the upper part of the sand which underlies the peat. The skull was reported as found at about the same depth, but it was quite certainly not in the sand.
The exact location of the skull was in section 22, township 23 north, range 6 east, within the area of the Illinoian drift-sheet, but the Wisconsin drift is not far away. The valley of the Illinois River in this county is mapped by Leverett as occupied by sands and gravels of Wisconsin age. Probably the animal lived when the Wisconsin ice-sheet was not far distant.
The skull described apparently belonged to a rather small, perhaps not fully grown individual. For purposes of comparison with other skulls, as the one found at St. Louis, Missouri, and the one found at Hebron, Indiana (p. [252]), the following measurements have been taken of this skull:
| mm. | |
|---|---|
| From tip to tip of horn-cores | 437 |
| Height of rear of skull from bottom of condyles | 168 |
| Width across the mastoid region | 183 |
| Width between hinder ends of temporal fossæ | 117 |
| Width at space between bases of horn-cores and orbits | 127 |
| Width at the rear border of orbits | 231 |
| Length of rough surface of forehead, at midline | 200 |
| Fore-and-aft width of base of horn-core | 98 |
| Vertical thickness of base of horn-core | 78 |
| From front of foramen magnum to rear of nasal bones | 260 |
The exostosis between the bases of the horn-cores is longitudinally deeply excavated, the excavation being 50 mm. wide and 27 mm. deep. The tips of the horn-cores come forward only even with the rear border of the orbits. In some other cases the horn-cores come forward to the front, or even in advance of the front border of the orbits. It is possible that this Manito skull was that of a cow.
3. Alton, Madison County.—In a collection of fossil mammals made at Alton by William McAdams and now in the U. S. National Museum is a single tooth, a lower left second molar, referred with some doubt to Symbos promptus. The crown is 34 mm. long and 25 mm. wide at the base. The tooth has been described briefly by the writer (Proc. U. S. Nat. Mus., vol. LVIII, p. 115). A list of the species accompanying it will be found on page [339].