IQ ON THE FRESH-WATER GLACIAL DRIFTS 



in considerable number where the remains of the mastodon and elephant must be 

 referred to the more ancient beds of the unmodified glacial drift, and even to the 

 tertiary of the Mississippi valley. 



The well preserved mastodon at Aurora, Illinois, was imbedded in a recent 

 swamp. Mr. Morris Miller, of Hanoverton, Columbia county, Ohio, is in posses- 

 sion of the grinder of a horse, and the tooth of a bear, which he found in a 

 position that he considers to be on the true drift. In the valley-drift of Yellow 

 creek, in the same county, Mr. E. White, C. E., took from a cut on the Cleveland 

 and Pittsburg Railroad at a depth of 30 feet, the jaw of a pachyderm, which was 

 exhibited at the Cincinnati meeting of the American Association, in May, 1852. 



On page 218 of Prof. Emmon's "Manual of Geology" is a figure of the crown 

 of the grinder of a horse, taken from the Post Pliocene beds of North Carolina. I 

 have a tooth from the compact marine drift of Long Island, taken by J. A. Bailey, 

 Esq., from excavations at Fort Schuyler, at Throg's Neck (18) eighteen feet below 

 the surface ; specifically identical with that figured by Prof Emmons. Another 

 one is before me, procured by INIorris Miller, Esq., in the valley of Sandy creek, 

 Columbiana county, Ohio, 530 feet above Lake Erie. It was thrown out about 

 twenty years since in making the Sandy and Beaver canal, in connection with bones 

 of the mastodon. Their depth cannot be fixed, but could not have exceeded 

 twelve or fifteen feet. The material is a modification of the fresh-water drift, not 

 far from the southern limit of the boulders, belonging, therefore, to the most ancient 

 alluvium. 



In this position most of the bones of the mastodon have been found, while those 

 of the elephant are often seen in the unmodified drift. It is the same with the 

 Castoroides Ohioensis and the tapir-like jaw of Yellow creek. Joseph Sullivant, 

 Esq., of Columbus, Ohio, many years since obtained from the crevices of the Cliff 

 limerock on the west bank of the Scioto river at that place a number of bones 

 imbedded in red clay. One of them he regarded as belonging to the Hippotherion. 

 Among them was the grinder of a horse, which unfortunately has been mislaid. 

 The crevice had not been open since the date of the white settlement of the country, 

 and was wholly filled with the compact red clay which results from the decomposi- 

 tion of limestone containing iron and filtration. A layer of the ordinary drift mate- 

 rials of the region, apparently undisturbed, lay over it several feet thick. 



Shells from the Drift and other Superficial Materials of the Northioest. 



Clevehmd, Ohio. — Helix arborea. Helix solitaria. Blue clay twenty feet above 

 Lake Erie. Helix fallax, upper and yellowish portion of the clay. Helix stria- 

 tella [or omphalus], 40 feet above Lake Erie. Fragments of Melania said to have 

 been found 100 to 120 feet above the lake, at the base of the sand ridges. 



Milwa^ikee, Wiscon,si?i. — Planorbis campanulatus, Paludina decisa, Melania 

 depygis, Lymnea desidiosa, Cyclas similis. Twelve to twenty-four feet above lake 

 level, in yellowish compact clay and hardpan. 



Dubuque, Iowa. — Two varieties of Cyclas, one crenated resembling Castalia, in 

 the Loess-like loam, 150 to 180 feet above low water in the Mississippi. Lymnea 



