On the Nummulite Limestone of Alabama. 189 





careous series crop out from beneath the horizontal and incumbent 

 beds of sand and clay. This twofold composition of the mass of 

 strata in the bluff at Claiborne, is expressed at A, in the annexed 

 wood-cut, (fig. 1,) and I verified a similar mode of juxtaposition 



Clni- Alabama 

 borne. River, Clarke County. Bettis's Hill. 



I. Eocene sand, marl, <fcc, with numerous fossils. — 2. White or rotten lime- 

 stone; Zeuglodon, nautilus, &c, eocene. — 3. Orbitolite limestone, eocene 

 4. Overlying sand, clay, &c, eocene. 



of the two series of beds in several places in the interior of Clarke 

 County, where the limestone often ends abruptly and is succeed- 

 ed sometimes in the same ridge or hill by the newer beds, (No. 4.) 

 the latter having evidently filled up the inequalities of a previous- 

 ly denuded deposit, after which the whole was again denuded. 



I have suppressed several details and repetitions of the same 

 phenomena in the country represented in the above diagram, 

 (%• 1,) and have been obliged to give a considerable inclination to 

 the strata, because in the distance of twelve or more miles between 

 Claiborne and Bettis's Hill, although the dip is not perceptible to 

 the eye, the same beds are at the latter place more than twice as 

 nigh above the Alabama river as at Claiborne. The mass No. 1, 

 about one hundred feet thick at Claiborne, which constitutes the 

 lowest visible member of the eocene series in this region, compri- 

 ses marly beds with Astrea sellceformis seen at the base of the 

 cliff at Claiborne, and an argillaceous stratum with impressions of 

 j^aves and sandy beds, with marine shells among which are found 

 Carditaalta andCardita planicosta, Cardita parva, Crassatella prac- 

 texta, Cytherea asquorea, Oliva Alabamensis, Pleurotoma (sev- 

 eral species), Solarium canalicaletum, Crepidula lyrata, Endopa- 

 c [jys alatum, Lonsdale, and two hundred other species. No. 2, 

 ab out fifty f eet thick, is the white or rotten limestone, which is 

 sometimes soft and argillaceous, but in parts very compact and 

 calcareous, and contains Flabellum cuneiforme, Lonsdale, Scutella 

 L yelli, Conrad, Lunulites, and several shells, some peculiar, others 

 common to the formation below. Mr. Conrad has already de- 

 cked this section at Claiborne, and I hope soon to give a fuller 

 notice of it with the observations which I made there in 1846. 

 U1 the limestone, No. 2, only the lower portion is seen here, for it 



