70 Bulletin 15 380 



Prof. Winchell.t in 1856, discriminated between the upper and 

 lower beds of the White limestone, noting that Orbitoides mantelH 

 is limited to the upper part of the formation. 



Salt Mountain limestone. Messrs. E. A. Smith, Langdon 

 and Johnson,* in 1894, found these divisions of the limestone 

 present throughout its di.stribution in the state. At one locality. 

 Salt Mountain, Clarke County, a third division was observed. 

 This overlies the others, and is composed of hard limestone, char- 

 acterized by corals and echinoderms. It attains a depth of 

 150 feet. The authors are inclined to think that it is a continua- 

 tion of the Vicksburg series which it overlies. 



The Vicksburg Ihnestone. The Vicksburg division is a soft 

 limestone, 140-150 feet thick, which hardens on exposure to the 

 air. It is chara(?terized by, and in layers composed of, the shells 

 of Orbitoides mantelli. 



Jackson limestcne. The Jackson division is a more argillace- 

 ous limestone, about 50 feet thick, and is charadlerized by bones 

 Zeuglodo7i. 



Grand Gulf series. The Grand Gulf sandstones reach their 

 eastern limit in south central Alabama. Near Oak Grove, Florida, 

 the typical sandstone beds pass beneath the Oak Grove sands, 

 indicating that the sandstone is approximately of the same age as 

 the Chattahoochee. 



In Alabama the typical sandstone is rare. The series usually 

 consists of clayey sands, or joint clays of a bluish, pink, purple, 

 grey or creamy white color. 



Chipolan species in Grand Gulf sands at Roberts. At Love- 

 lace's Mill, near Roberts, a black sand, three or four feet in depth, 

 was observed b}' Mr. Johnson. This was found to contain Car- 

 dium chipolanum and species of Cardita, Lucina, Macoma, Area, 

 PeHunculus and Crassatella. Dr. Dall correlates the bed with the 

 Chipola division. 



* Proc. Anier. Assoc, 1856, pt. 2, p. 85. 

 \ Rep. Coastal Plain of Alabama, 1894. 



