MASTODONS, MAMMOTHS AND OTHER PLEISTOCENE MAMMALS 83 



tibia of a fossil phocid near Cystophora cristata 

 Erxleb." 53 



This fossil had its origin in the Pleistocene sea which overspread 

 the area now occupied by Lake Champlain and the adjacent parts 

 of New York and Vermont and is doubtless of the same age as the 

 remains of the fossil cetacean unearthed in August 1849 on the 

 Vermont side of the lake, 12 miles south of Burlington and about 

 1 mile east of the lake shore. 54 



Castoroides ohioensis Foster Fossil Giant Beaver 



The .remains of this giant rodent were first discovered in Ohio 

 associated with the bones and teeth of Mastodon, Elephas, Ovis and 

 other mammals. S. R. Hildreth 55 presented the earliest account of 

 the species but failed to give it a name; this was later supplied by 

 the geologist, J. W. Foster. 56 



In New York State remains have been found in two localities. 

 The first were discovered (1845) m a swamp on the farm of Gen. 

 W. H. Adams of Clyde, during the construction of a canal extend- 

 ing from Sodus bay, Lake Ontario, to the Erie canal about 1 mile 

 west of the village. The well-preserved cranium is now in the New 

 York State Museum (plates 20, 21). 



The geological position of the fossil was fully discussed by James 

 Hall, 57 who stated in part: "The situation in which it was found 

 is an elevated plateau or level tract of land . . . the whole 

 surface [of which] is covered by a peaty soil. . . . This ele- 

 vated ground is the summit level, from which the waters flow in 

 opposite directions, into Lake Ontario on the north, and into the 

 Clyde river, and thence into Cayuga and Seneca lake outlets on the 

 south. The precise locality of the fossil was near the termination 

 of a shallow ravine, or the bed of a small stream, which flows into 

 Lake Ontario, in a northeasterly direction." 



A section at the locality presented the following characters from 

 the top down: 



" 1st. Muck, or vegetable soil ... 2 feet or more in thick- 

 ness. 



" 2d. Fine sand, with occasional thin bands of clay, often con- 

 sisting of alternating layers of sand, twigs, leaves and other frag- 

 ments of vegetable matter; . . . 2 to 3 feet thick. 



68 S. C. Bishop, Jour, of Mammalogy, 1921, 2:170. 



M Zadock Thompson, Amer. Jour. Sci., 2d ser., 1850, 9:257. 



"Arner. Jour. Sci., 1837, 31:80-81, figs. 15-18. 



^Geol. Surv. Ohio, 2d Annual Rep't, 1838, p. 80-81. 



"Bost. Jour. Nat. Hist. 1846, 5:385^1, 3 pi. 



6 



