OCT. — DEC. 1856.] of the Southern Division. 95 
the oxide of iron. Farther to the north where other smaller ra- 
vines come into the large one a still lower stratum is laid bare, it 
consists of a well-defined gneissoid sandstone. It is plainly and 
evenly stratified with layers of mica, silicious sand and felspar, or 
lime. The stone is soft and friable and appears to be considerably 
extensive, underlying much of the western part of this plain, its 
thickness is unknown. In a bank in the lower part of the ravine 
were strata of a pure white clay, or chalk alternating with layers 
of a dark dun-colored substance of* the same apparent composi- 
tion ; both containing carbonic acid and effervescing freely with 
acids. This dun-colored clay is very extensive throughout this re- 
gion and becomes indurated and passes into limestone. Much of 
the recent limestone in which the shells are imbedded is evidently 
formed from this clay ; as it exists in different parts of this plain 
underlying the cotton soil in almost every degree of hardness from 
that of marl and soft clay to that of compact and solid limestone. 
On the east side of this ravine, this clay and the cotton soil 
which commences here is overlaid with an earth containing salts 
of different kinds ; those containing nitrate and muriate of soda 
are conspicuous. The sulphate of lime in the form of bladed, 
amorphous, and fibrous gypsum was so prevalent as nearly to cover 
the ground in some places although some bandy loads had been 
collected and sent to Madras. In and on the banks of this ravine 
were found a large number of the shells called belemnites and spe- 
cimens of globular, cylindrical and over-shaped substances, of va- 
rious sizes from that of an ounce bullet to that of some six or 
eight inches in diameter and length. These substances were com- 
posed invariably of a dark blood-red or brown-jointed oxide of 
iron and laterite or fine radiating zeolite. Sometimes these round 
substances were inclosed as nuclei in nodules of pure white chalk ; 
but more frequently they were covered with a thin smooth cretace- 
ous substance, which gave them an uniform appearance as far as 
the texture of this external coat was concerned. 
In our farther examination of this interesting locality, it was 
found, that this black soil and these globular specimens of fossil 
Crustacea, (as there is evidence to believe they are), extended to 
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