CALCIFEROUS SANDSTONE. 5 
CALCIFEROUS SANDSTONE. 
We find in this rock, in numerous localities, a great number of what appear to be the 
remains of sea plants. Many of these consist apparently of fragments of large succulent 
stems, even giving some evidence of having been hollow, like the stems of some of the 
marine plants of the present day. It is impossible in these, as in nearly all the remains of 
marine plants of the paleozoic rocks, to detect any structure which can be reliable in 
making distinctions. In the case before us, we are led to refer these vestiges to marine 
vegetation, not from their appearance alone, but from the fact that we find, in cavities 
of the same rock, small quantities of anthracite. Now although the present condition of 
this carbonaceous matter is that of anthracite, we nevertheless believe it to have been a 
fluid or semifluid bitumen, from the fact that where occurring free in a cavity of the rock, 
it has indurated in a globular or semi-globular form, indicating a degree of fluidity in its 
original condition. The very natural suggestion is, that the bituminous matter derived from 
this vegetation has parted with its volatile parts, and become a solid mass of non-bituminous 
coal. Whatever weight such an argument may have, we cannot resist the inclination to 
associate this production with the obscure remains which we find in the same strata. 
From the nature of the rock, and from the condition of many of its fossils, we cannot 
doubt but many more forms, both of plants and animals, were imbedded in it, than we 
find at the present time. The very obscure impressions and cavities which so frequently 
occur, in some of which it is not difficult to detect the marks of organic structure, lead us 
to believe that the sea from which this deposit was thrown down contained a numerous 
fauna. That their remains are so obscure at the present time, has doubtles arisen from two 
causes : first, that during the deposition of the mass, there was a considerable intermixture 
of silica, which to some extent existed in a soluble condition, and, as we infer, absorbed 
the exuvie and obscured the characters of these remains ; and again, the proximity of this 
rock, in its best defined localities, to those of hypogene origin, and the numerous faults 
and uplifts it presents, lead us to believe that it has undergone subsequent changes, which 
also may have had some effect in obliterating the organic forms. 
In nearly all instances, we find the shells removed, and siliceous casts of the interior 
only remaining. In a few instances, the shell is replaced by siliceous matter. Many of these 
casts are imbedded in a mass of chert or hornstone, the material of which has doubtless 
been aggregated around them after their death, forming nodules or accretions as in the 
higher limestones and in chalk. 
During the progress of this formation, and towards its close, a considerable number of 
forms of animal life appear to have been called into existence. We have passed from that 
