Monmouth County has furnished more fossil vertebrates of the Pleistocene than any other county. Mastodons have been discovered at Englishtown, Freehold, Marlboro, Long Branch, Manasquan, and in the Navesink Hills (pp. 65, 66). Many specimens, as those about Freehold and Long Branch and Manasquan, are in such superficial positions in peat that they do not seem to be very old, probably of Cape May age; and yet of this one can not be wholly certain. The discovery of a heel-bone of a megatherium (p. [31]) at Long Branch appears to indicate the presence there of early Pleistocene deposits. At Englishtown the remains had apparently become mixed with marl, and they may belong to an older stage of the Pleistocene. In the Navesink Hills, according to Leidy, the mastodon remains were associated with those of an extinct horse (p. [184]). If so, both species probably were buried in Pensauken deposits. In this same region there was found long ago a tooth of Elephas columbi (p. [149]); but it is useless to speculate on its geological age. At Long Branch (p. [26]), damaged skulls of walruses, probably of the existing species, have been met with. It seems natural to associate this southward migration, which extends to South Carolina, with the Wisconsin epoch; but it is possible that it was earlier. At Deal (p. [227]) have been found remains of a deer, probably Odocoileus virginianus.
Fig. 8.—Sketch of vicinity of Trenton, showing distribution of Trenton gravels. Redrawn from Salisbury and Knapp.
Fig. 9.—Sections taken at Trenton, New Jersey.
Upper figure taken along the line 3 of Fig. 8.
Lower figure taken along the line 2 of Fig. 8.
The black represents the glacial gravel. A, the crystalline rock of the region; T, Trias; K, Cretaceous; Pp, Pensauken; O, sea-level.
Somewhere about Shark River, a tooth of a peccary (p. [213]) was found, as was supposed, in Miocene marl. Leidy could not distinguish this tooth from that of Mylohyus nasutus. So far as our evidence goes, this species belongs to the early and middle Pleistocene.
Near North Plainfield a tooth was found which is referred to Elephas primigenius (p. [133]). The locality is very close to the moraine of the Wisconsin ice-sheet, and the animal probably lived there when the Plainfield outwash plain (Salisbury, Geol. Surv. New Jersey, vol. V, 1902, p. 738) was being laid down.
Near Schooley’s Mountain, but west of Musconetcong River and in Warren County, remains of a mastodon (p. [67]) were encountered in excavating the Morris Canal. It is probable that these were buried in a swamp left over from the Wisconsin times; but Lewis and Kümmel’s map of 1910–1912 indicate in this region only drift older than the Wisconsin.
The mastodons found at Hackettstown and Hope, in Warren County, are probably of Late Wisconsin origin (pp. 67, 68).
Near Mount Hermon, about 5 miles northeast from Delaware, in Warren County, and about 2 miles northwest of Hope, was found the splendid skeleton of the moose Cervalces scotti, which forms one of the treasures of Princeton University (Scott, Proc. Acad. Nat. Sci. Phila., 1885, p. 174). It was discovered in a bog. All this region is (Salisbury, Geol. Surv. New Jersey, vol. VIII, plate XXVIII) occupied by Wisconsin drift and the bog doubtless rested on this drift. It seems certain, therefore, that this stately relative of our existing moose lived after the disappearance of the Wisconsin ice-sheet.