vated to the depth of about six feet under one of the ledges, and found 
that the stone had entirely decomposed, leaving the tubes smooth and 
perfect, filled with variously colored sand. The fact that the sandstone, 
is so much decomposed under the surface, has led me to think that 
__ much of this sandy region in Alabama has been formed by the wearing 
away of this formation. The evidences tend to show that it extended 
over a large portion of South Alabama, but organic remains are dis- 
covered only ina few places. It is questionable whether impressions 
of ‘shells can be found in any other place than the one I have mention- 
ed, and there the extent of surface exposed is not a rod square. 
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“The above is a section of the upper part of a abs showing © the 
relative position of the tubes and the strata, and an appearance of having 
been undermined at one end.. Wherever I have seen the sandstone 
80 as to mark the strata, they are about as above, except at the lowest 
Place, mentioned as 40 feet below the strata containing shells, and 100 
below the above ledge, where the angle of inclination is 15°. There 
isa ledge five miles distant from the above, where fragments of tubes 
are found, much more elevated, as high probably as any portion of the 
country. Another locality where I found silicified wood, in fragments, 
Scattered abundantly over the ground, is nearly as high as the last men- 
tioned ledge. 
~The tubes are generally round or oval, from one half inch to 12 
inches in diameter of various lengths,—I saw one six or seven feet 
long, and six inches’ in diameter ;—they are not always perfectly 
Straight, but generally curved or a little crooked ; the layers are con- 
centric, and vary in thickness; the stone forming the tube is some- 
times an inch thick. ‘Where they are exposed to the air, they are 
hollow ; beneath the surface they are filled with sand as before described. 
One : specimen of the tubes containing silicified wood is six inches 
long and oval as if it had been compressed, an inch and a half in the 
Sreater diameter ; the rings are very distinct in the wood, and it was 
: en! surrounded with stone. Some specimens of the wood had un- 
partial decomposition.” 
