54. _Holley, Orleans County._—In 1843, James Hall (Geol. 4th Dist., p. 364) reported that during the excavation of the Erie Canal, a large molar tooth was found in a swamp near Holley. This, according to Clarke, was about 1820. At the earliest time assignable, this mastodon lived after the Wisconsin glacier had withdrawn nearly into the basin of Lake Ontario. It may have had its existence nearly up to the Recent epoch. 55. _Medina, Orleans County._—In the Buffalo Society of Natural History is a part of the left ramus of the lower jaw of a mastodon, labeled as having been found in a swamp near Medina. It contains the second and third true molars. The remark about the geological age of the Holley mastodon is applicable to this one. 56. _Niagara, Niagara County._—In 1842 (Zool. N. Y., Mamm., p. 104), De Kay stated that a mastodon tooth had been found in digging a mill-race on Goat Island, 12 or 13 feet below the surface. Lyell, in 1843 (Ann. Mag. Nat. Hist., vol. XII, p. 127), alluded to the occurrence of remains of mastodon in a fresh-water formation on the right bank of the Niagara River at the Falls. The formation appears to have consisted of gravel. These are possibly the same remains as those mentioned by De Kay. Hall (Geol. 4th Dist., p. 364) stated that the deposit was a fine gravel and loam containing fresh-water shells, and evidently of fluviatile origin. These deposits were noted by W. E. Logan (Geol. Canada, 1863, pp. 913–914). On the Canadian side of the gorge below the Falls, 16 species of fresh-water mollusks were found in the sand, evidently where they had lived. At the museum of Davis Brothers, at Niagara Falls, Mr. B. U. Davis told the writer that he owned 2 mastodon teeth which had been found in digging for the foundations of the Tower Hotel, which faces the Falls park. Mastodons could have lived where Niagara Falls is now located only after the Wisconsin ice-sheet had retired far enough to permit the waters of Lake Iroquois to fall somewhat below those of Lake Erie, the shrinkage of the latter to its present basin, and the formation of dry land or land not too swampy around the present Niagara Falls. 57. _Hinsdale, Cattaraugus County._—Hall (op. cit., p. 364) stated that at this place a tusk, with some horns of deer, had been found in gravel and sand, 16 feet below the surface. Clarke (Bull. 69, etc., p. 933) mentions this case and suggests that the antlers were possibly those of the elk. The tusk may quite as well have been that of an elephant. Lyell (Ann. Mag. Nat. Hist., vol. XII, 1843, p. 127) referred to this discovery as showing mastodon bones at the highest elevation known at that time, 1,500 feet above the sea.