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the character and structure of the country generally, that the unaltered 

 or mother rock is the rock of the region i. c., that the Orbitoitic sees 

 its true development here. 



The same admixture of rocks is again observed at an outcrop on the 

 right bank of the river, about one mile further up the stream. About 

 three miles above this second point, in a clearing known as Loenecker's, is 

 the famous nummulite locality where Mr. Willcox obtained the original 

 nummulites described by me in 1882. The rock lies here in loose 

 masses in a partially ploughed field, about four to six feet above the 

 surface of the water. No indication of a true outcrop could anywhere be 

 detected, but I am satisfied that the parent rock either immediately 

 underlies the locality, or is found in its immediate vicinity. The very 

 insignificant elevation of the entire region above water-level, its uniform 

 horizontality, and the dense capping of vegetable matter beneath which 

 it lies buried, necessarily reduce to a mininum the chances of finding an 

 outcrop, and explain why to so many of its inhabitants this portion of 

 the State is supposed to be wholly destitute of solid rock. Even along 

 the river-courses, where we should most naturally expect to meet with an 

 exposure, the vegetable growth is so dense and impenetrable as to prac- 

 tically completely hide the fundament, and were it not for an occasional 

 or accidental clearing, such as Loenecker's, one might be left in absolute 

 ignorance of its very existence. 



The rock occurring at Loenecker's is of two kinds one, in which 

 almost the entire mass is made up of the tests of orbitoides, and the 

 other in which the nummulites predominate to about the same extent. 

 But several of the larger fragments indicate the most unmistakable inter- 

 association of the individuals of both these genera of Foraminifera, and 

 leave no doubt as to the equivalence in age of the two classes of deposit. 

 The Orbitoides found here represents two or more species, one of the 

 type of the well-known Biarritz fossil, 0. cphippiiun (0. sclhi), whose 

 peculiarly infolded tests are very abundant, and another more nearly 

 recalling O. dispansa. I am not sure that I recognized any undoubted 

 0. Mantclli, the form of the Mississippi and Alabama " Vicksburg " 

 beds, but not impossibly some of the smaller tests referred to the 0. 

 dispansa type may represent arrested forms of this species. Both species 

 of nummulites occur here, i. e., Niniunulitcs \Villcoxi and A". Floridcnsis, 

 the former very largely predominating. 



With reference to the physical history of these deposits, I can per- 

 haps not do better than quote my own words published at the time of 

 their discovery (Contributions to the Tertiary Geology and Paleontology 

 of the United States, p. 81, 1884): "As to the age of the formation repre- 

 sented by these nummulitic deposits, there might appear to be at first 

 sight no question of doubt. The presence alone of nummulites in any 



