548 CENOZOIC TIME. 



the lower part may be the equivalent of a portion of the Orange sand. Above the Port 

 Hudson group, and a deposit overlying it, thirty to seventy feet thick, without bedding, 

 distinguished as " loess " by Hilgard, there is generally a thin deposit of yellow loam. 



A peat bed of the Alluvian era, a mile east of Germantown, Montgomery County, 

 Ohio, has been described by Prof. Edward Orton. 



The loess of the Mississippi contains numerous fresh-water shells, among them Palu~ 

 dina ponderosa Say, Melania canaUcidata Say, Cyclas rivularis Say, Cyclostoma lapi- 

 daria Say, Physa heterostropha Say, Limncea elonyata Say, Planovbis bicarinata Say, 

 Valvata tricarinata Say, Unios, etc. 



Level of the Formations. — The height of the river-border formations, 

 as well as those about lakes, above the level of the adjoining river or 

 lake, (1) increases on going north, over most parts of the continent, 

 in Drift latitudes ; being, along the larger streams, in Southern New 

 England, 45 to 60 feet; in Massachusetts, on the Connecticut, 136 to 

 200 feet ; north of Massachusetts, along the same river, from Vernon 

 to Hanover, 200 to 240 feet ; on Lake Ontario and the Great Lakes, 

 300 to 500 feet. 



But (2), where a river becomes much diminished in size toward 

 its source, the height of the upper plain diminishes, notwithstanding 

 the increased northing, on the general principle that all small streams 

 have small alluvial formations, whether modern or ancient. 



Also (3), if a stream has falls or rapids, or a rocky bottom, the teiv 

 races are lower on this account. 



Heights of Upper Terraces, east of Rocky Mountains, above the level of rivers or lakes. 

 — On the coast, along the southern borders of New England, as at the mouth of the 

 Connecticut, or at New Haven, the height of the upper plain above the river is about 

 45 feet; at East Hartford, Ct., 36 miles north, 60 feet; at East Windsor, Ct, 48 miles, 

 71 feet; at Long Meadow and Springfield, Mass., 62 miles, 136 feet; at Willimansett, 

 Mass., 68 miles, 194 feet; below Bellows Falls, Vt., near Walpole, 226 to 243 feet; at 

 Brattleboro, Vt., 200 to 221 feet; at Windsor, Vt., 207 feet; at White River Junction, 

 Vt., 209 feet. (Hitchcock.) Measuring from the existing flood ground, the height at 

 New Haven, Ct., is 40 to 45 feet; at Hartford, about the same; at Springfield, 112 feet; at 

 Willimanselt, 170 feet; at Walpole, N. H., 190 to 208 feet; at Hanover, N. H., 182 feet. 



The sandy terrace between Schenectady and Albany, N. Y., and opposite the latter 

 place, east of the Hudson, is 330 to 335 feet above the river, but whether true stratified 

 Drift at top is not certain. On the Genesee, east of Portage, the upper level is 235 

 feet above the river. 



The ridge road or terrace, south of Lake Ontario, 190 feet above the lake, the greatest 

 height (Hall); terrace south and southwest of Lake Erie, 220 feet; north of Lake 

 Ontario, at Toronto and other points, 30 to over 500 feet; the Davenport ridge, west of 

 Toronto, 250 to 300 feet; west of Dundas, west end of Lake Ontario, 318 feet (under the 

 escarpment of the Niagara formation, which is 100 feet higher); near Fredericton, New 

 Brunswick, on the St. Johns, 345 feet above the river; at other points below, on the 

 same river, 350 to 400 feet. On the north side of Lake Superior, the maximum re- 

 ported, 331 feet above the lake ; near Lake Huron, clayey deposits, at different levels 

 up to about 500 feet. On the Lower Ohio, 50 to 160 feet; near Louisville, 52 and 128 

 feet above low water, or 10 and 86 feet above high water: near Cincinnati, 100 to 120 

 feet above low water. On the Mississippi, in Tennessee, 50 to 180 feet; at Fort Adams, 

 Loftus Heights, 163 feet (made up of 90 feet of Orange Sand and 73 of loess); at New 

 Orleans, about 60 feet. On the Missouri, in Platte County (N. W. Missouri), 335 to 

 150 feet. Atchison County, 250 to 150 feet. On the Red River, in Texas, 50 to 100 feet. 



