Mississippi and Alabama. 203 



is plainly southern, as the clays (No. 1 of my section 1) are 

 seen at the water's edge here. For several miles nothing is 

 seen along the river bank, but finally at a point ten miles 

 by river (about six directly) above Byram the " lignitiferous 

 sands" mentioned by Hilgard* first appear as in Section 2. 



Pearl River Section, JVo. 2. 



1. Laminated gray micaceous sands very slightly argilla- 



ceous, containing fragments of leaves, and bits of 



lignitic matter, but no fossils distinguishable 4 feet. 



2. Earthy lignite 3 feet. 



3. Gray micaceous sands to water level 6 in. 



The strata show at this point a dip of about twenty feet in a 

 hundred toward the south. The exact point of contact with 

 the Jackson clays is not seen, but the gap between this section 

 and the last exposure of my No. 1 of section JSTo. 1, is not 

 more than a quarter of a mile, and as both show a southern 

 dip, the natural inference is that their distance apart vertically 

 cannot be great. About a quarter of a mile still farther down 

 the river there is an evidence of slight rolls in the strata, but 

 the tendency of the dip still remains southerly. A gap of 

 about a quarter of a mile then occurred and the gray sands 

 when next seen were dipping southward very rapidly, as much 

 as five feet in a hundred, and fully fifty feet of strata are ex- 

 exposed. This dip, as well as the one previously noticed, is 

 abnormally great, and is probably due to some local disturb- 

 ance. In the upper part of the fifty feet observed, the sands 

 became somewhat indurated, forming overhanging ledges two 

 or three feet thick, the lower portions contained bits of lignitic 

 material and pyrite ; a large log two feet in diameter and com- 

 pletely lignitized, was also seen. Another gap of about a 

 quarter of a mile occurred and then appeared the first evi- 

 dences of Vicksburg strata in a high bluff on the east bank of 

 the river, where the following section is seen : 



Pearl River Section, JVo. 3. 



Surface soil, growth mainly Pinus australis. 4 feet. 



1. White limestone, upper portion decomposed, lower 



part harder and slightly crystalline ; contains Orbi- 

 toides Mantelli\ Mort., Pecten Poulsoni Mort., and 

 casts of several bivalves. 4 feet 



2. Gray calcareous clay containing Pecten Poulsoni Mort., 



and other fossils all very friable 4 feet. 



3. White limestone containing some indurated irregular 



ledges, — no fossils seen 5 feet. 



* This Journal, p. 268, No. 178, vol. xxx. 



f Under this name I include the two species usually ascribed to this genus. 



