27 



Subcarboniferous (Umbral, &c, of Roger,) underlying the anthracite basin 

 of Pennsylvania, and extending southward to North Carolina, and also with 

 the New Red Sandstones of the Lower Permian. Of course, in this comparison 

 the difference of the epochs has to be taken into account. But in all these 

 formations we remark a peculiar compound without relation to past and 

 sequent formations; a great uniformity of these compounds which are much 

 alike at the different epochs ; a nearly total absence of animal remains, and a 

 flora, exclusive in its characters and without marked relation to the floras of 

 corresponding times. The origin of these groups of red sandstone is the same, 

 to my belief, at least. They are beach formations, like those in progress at the 

 present time along the shore of the North Sea, in Holland and Belgium, where 

 the widely extended muddy shores are formed of a soft substance of the same 

 red color. As I have had opportunity to observe it, it is a mixture of small 

 grains of sand, brought from the sea, with the mud deposits, carried by rivers of 

 longcourse, after traversing flat countries. By slow deposition, it constitutes low 

 shores, successively washed by the tides, which, of course, recede or advance 

 farther in proportion to the slow upheaval or to the depression of the land. 

 Marine animals, the shells especially, are very rare in a formation of this kind. 

 It has only a few species mostly of small size ; also the prints of the tracks of 

 Saurian, of birds, &c, the ripple-marks, the cracks or the preforation caused 

 by atmospheric influences, dryness, heavy rain or hail. But it is shunned by 

 every kind of land animals, and it has, therefore, no other remains imbedded 

 into its compound but Saurians, and rarely fishes. 1 Its flora is for the same 

 reason of a peculiar character. It has no remains of marine plants, for these 

 do not grow on the mud or upon soft ground ; the vegetation of high dry land, 

 and also that of the bogs or of the peat, are excluded from it ; the first on 

 account of the humidity and softness of the ground, the other from its con- 

 stant alternance from a dry to a submerged surface. 



The character of the leaves found in the Dakota group, and their analogy 

 with species of our time, seem at first to refer them to a dry-land flora; it 

 is, however, not positively the case. The most abundant representative of this 

 Cretaceous flora, the Sassafras, is remarkably similar to the present Sassafras 

 officinale, which inhabits every kind of ground and station, from the dry.hills 

 of Ohio to the low swamps of Arkansas. The numerous leaves of Laurus, 

 too, are comparable to those of Laurus caroliniana, a shore plant, as are also 



1 Iu Holland tlio ditcbcs across tbo flats, where water is permanent, are mostly inhabited by eels 

 in prodigious quantity. 



