GEOLOGICAL RELATIONS. J^gl 



Wabash River, in that State. It is a fine sandy marl 

 of a yellowish-white color. It occurs on the upland, 

 from twenty-five to fifty feet above the bottom land, and 

 is reached at the distance of from six to ten feet from 

 the surface, and has been penetrated to the depth of 

 twenty-five feet without passing through it. It appears 

 also on the opposite side of the Wabash in Illinois at 

 about the same level, and near Shawneetown, forty miles 

 distant, in descending into the bottom land, in a similar 

 position. Dr. Owen has learned that a similar deposit 

 in an analogous position exists opposite to St. Louis, 

 above the American bottom on the INIississippi river, and 

 there are said to be indications of a like formation at 

 Big-Bone Licks, on the south side of the Ohio River, 

 about twenty miles below Cincinnati. The Wabash 

 deposit contains, in vast numbers, terrestrial and fluviatile 

 shells of the same species as those now existing in the 

 surrounding country ; they occur also, as we are informed, 

 in strata of marl below the deposit in which the bones 

 of the Mastodon are found.' Whether all these are 

 parts of one continuous deposit, or whether they point 

 out the location of several small basms in which a con- 

 temporaneous deposition took place, is not yet ascer- 

 tained. The fossils which they contain prove, accord- 



* The number of land and fresh-water shells occurring in the "Wabash 

 deposit is very great. In a small parcel of the marl which we have exam- 

 ined, the following species were noticed. Helix hirsuta, monodon, laby- 

 rinthica, lineata, tkyroidus, claicsa, infiecta. Pupa armifera, coiitracta. 

 Hdicina occulta ; together with several species of lamineu, Planorbis^ Am- 

 nicola, Valvata. 



