13o GEOLOGICAL • [T214 



wiiich distinguishes as widely the several stages < ; the Si i Eocene of 



the United States, as even the primary divisions of the entire Tertiary of the old 

 oentinent. 



The perfect state of preservation in which we find the fossils of this Red Bluff 

 Group, the easy accessibility of its strata, a^d withal the narrow limits to which, 

 thus far, T have found it to be confined — the bluffs of the Chickasawhay from 

 Trotter's plantation (where the ferruginous rock, peculiar to this group, first 

 appears on the hilltops — see ^212) to Red Bluff* Station, or a little below — 

 impart a special interest to this deposit. At low water, the sloping bed of the 

 Chickasawhay River may in spots be found strewn with perfect shells of this 

 group, washed down from above by the rains out of their easily disintegrated 

 clay matrix. I give below a list (for the compilation of which I am indebted to 

 Prof W. D. Moore, Univ. of Miss.) of the fossils thus far collected from this 

 stratum, determined so far as they are identical with species described by Conrad 

 and Lea, the rest being determined generically only. The species in common with 

 Vicksburg are marked with an asterisk* those in common with Jackson, by a 

 diggerf. 



Venericardia planicosta j. Busycon spiniger, Con.* 



Venericardia ? fc;* Fusm (1) (allied to 



Cypneardia. Con.*) 



Pecten nuperus. sus. 



Plagios'oma Turbinellaperexilis, I 



Ostre'i, 2 n. ? • Tarbinella protracto 



Pectuncut Murex, 3 sp. 



Astarte (allied to A. Triton. 



Gardium diversum, Con.* Rostellaria velata, CoN.f 



Gorbula. Buccinum Mississipp. Con.* ? 



Leda. Bttccii 



Gyiherea. Cassis. 



Denialium ihalloides, Con. ? Cassidaria tin tea, Con.* 



Natica Vicksburgensis, Con.* Fulgoraria Mississipp. Con.* 



Natica sigaretina, Con.* Caricella. 



Capulus. Conus saui >N. * ? 



Capulus. Bulla 2 n. sp. 



Pileolus. Solarium; 



Trodiita trochiformis, Con. Flabellum Wailesiir, Con. f? 



Mitra Mississippiensis, Co Osteodes, Con. / (not 0. irroratus). 



Gypraea sphaeroides, Con. Madrepora (allied to M. Missis. 



Glavelith s is, Con ?f Con.*, but distinct.) 



Glavelithcs. pula. 



Pyrula 2 n. sp. 



Southward of the locality mentioned the green clay (No. 3 of Sec. 28.) appears 

 in greater thickness ; it is this, no doubt, from which the heavy soil on top of 

 tho terrace, or "hommock" (which closely resembles the <: hog-bed" soil of Jasper, 

 and is so termed by the inhabitants) is derived — intervening, here as elsewhere, 

 between the prairies of the Jackson and Vicksburg Group. Crystals of selenite, 

 also, have been obtained from the banks of the river, and from wells, in this 

 neighborhood. 



214. Lignitie Beds. — At Vicksburg and at Brandon, lignitic clays and sands 

 underlie the lowest visible strata of the Vicksburg Group. Whether or not 

 similar beds are traceable on Pearl River and Chickasawhay, I have not ascer- 

 tained. At Vicksburg, about 25 to 30 feet of black lignitic clays and sands, and 

 lower down, of lignite, underlie the calcareous marine strata. The lignite was 

 supposed to extend to a considerable depth, but according to an observation made 

 by Prof. W. D. Moore, at extreme low water, its thickness docs not exceed 3 feet, 

 it being underlaid by a soft whitish limestone, of which ho obtained a small 



