196 GEOLOGICAL REPORT. [T330' 2 . 331 



Helix albolabris. Helix perspective/* 



" alternata. " profunda. 



" concava. " thyroides. 



" elevata. " tridentafa. 



" fraterna. 



To which I may add Helix ynonodm, and a large Achatiiia, found in Wilkin- 

 son county. 



The following list of the mammals found in a solid blue clay, said to belong 

 to this formation, was furnished to Prof. Wailesby Dr. Leidy : 

 Felis atrox, Leidy. Tapir us Haysii, Leidy. 



Ursus Americanus, foss. Equus Americanus, Leidy. 



Ursus amplidens, Leidy. Bootherium cavifrons, Leidy. 



Megalonyx Jeffersonii, Harlak. Cervus Virginianus, foss. 



Megalonyx dissimilis, Leidy. Bison latifrons, Leidy. 



Mijlodon Harlani, Owen. Eleph'as primigenius. 



Ereptodon priscus, Leidy. Mastodon giganteus, 



Tapirus Americanus, foss. 



Of these, the last named is by far the most common. The following localities 

 are mentioned by Prof. Wailes : Bayou Sara ; Pinkney ville, Wilkinson county; 

 various localities in Adams county ; near the former town of Greenville, Jef- 

 ferson county ; in Warren county, in the deep cut of the railroad at Vicksburg, 

 and in the vicinity of Big Black River, near the ea^t line of the county. In a 

 ravine on Pine Ridge, Adams county, in TT. 7. and 8, R. 3 W., about six miles 

 north of Natchez, these remains are very abundant. They are found about 

 twenty feet below the surface, and the bones of other animals are h?re found 

 associated with them ; e. g. the Megalonyx, Tapirus Americanus, the fossil horse, 

 and ox. (Wailes. ) t 



330. Useful Materials, and Waters of the Bluff Forma- 

 tion. — The calcareous silt of this formation is often a marl properly 

 speaking, when it. contains a large amount of white specks of car- 

 bonate of lime. Usually, its percentage of lime is too small to 

 pay for its transportation to any distance, forming simply a cal- 

 careous soil or subsoil ; but. on account of its general and conven- 

 ient accessibility, and its highly beneficial effects on the browa 

 loam soil, it may often be nixed with the latter to great advantage. 

 An analysis of this mateiial, and other specialities concerning the 

 same, will be found in the Agricultural Report. 



Small, local deposits of a soft limestone or tufa are sometimes formed by the 

 highly calcareous waters of this formation. The rock is generally of a yellow- 

 ish tint, very porous, and occurs in irregular masses, in which shapes resembling 

 icicles, or stalactites, are frequently seen. Sticks, leaves, etc., may sometimes 

 be lound imbedded in it, while the cavities are usually filled with soil. These 

 deposits may be looked for in the heads of hollows, or in the beds of branches, 

 wherever the water drips, in the Cane Hill region ; but their extent, as before 

 observed, is too limited to render them of any great practical importance ; they 

 lie on the surface and do not extend into the mass of the formation. The 

 impure liine which might be burnt from this material, would be applicable 

 mainly to agricultural purposes. — The largest deposit of this kind which I have 

 seen, occurs on Mr. J. 0. Humphrey's land, near Port Gibson. 



331 2 . Owing to the great uniformity of the material of this form- 

 ation, spririgs are very scarce on the territory occupied by it, 

 except where it is underlaid at the proper elevation by impervious 

 clay or sandstone strata of the Grand Gulf Group. The water 

 issuing from the calcareous silt is very "hard," of a flatfish taste, 



