12 
LEA’S DESCRIPTION OF A FOSSIL SAURIAN 
polished rhombic fish scales in the bituminous shales near Farmville, and at Leakes- 
ville, in North Carolina.” 
In regard to the character of the Molluscs which may have inhabited this formation, 
it is difficult to adduce them as much evidence, where so little is known. The 
almost total absence of fossil shells, or impressions, is most remarkable in the New 
Red Sandstone here, as it is, also, in Europe. In the Paleontological tables of M. 
D’Orbigny, there are a few genera given, as existing in his Saliferien, (the upper por¬ 
tion of the Trias,) and among the Lamellibranchia is the genus Posidonia, a species of 
which Prof. W. B. Rogers states he has found in Virginia, and which he refers to a 
well-known species in the Keuper, or uppermost division of the Trias , known as P. 
Keuperi* He also mentions that, in Cumberland County, Virginia, in the Yellow 
Brown Sandstones, he found a spiral univalve and a rhombic fish scale. 
To this I may add a minute species of Gasteropoda, which I suspect belongs to the 
genus Loxonema\ and which I have observed in a polished specimen of the Potomac 
Marble,f and for which I propose the name of Loxo. Poweliana. These are the oidy 
Molluscs which have been, to my knowledge, found in the New Red Sandstone 
of this country. The question might now be asked, are these of marine or fresh 
water origin ? I think it would be difficult to answer, with any degree of 
certainty. The shell of Posidonia has evidently been, in all the species, exceed¬ 
ingly fragile, and, as far as my knowledge extends, the casts only have been 
observed, and those rarely perfect*.. I doubt very much whether those found in 
the Carboniferous Formation can be properly placed in that genus, particularly if 
they be found in the slates of the coal seams, which are probably of fresh water 
origin.$ In the slates taken from the anthracite beds of Pennsylvania, I. have 
found bivalves, which I should consider so much allied to the form of Posidonia , 
as not to think of separating them, had they not been in a coal slate. At 
the same time, I must say that the same slate contained impressions of a 
lamellibranc, which has all the external characters of the genus Modiola; which, 
however, would not exclude it from fresh water origin, as we have a living genus, 
*But a few years ago it was considered in vain, Mr. W. King, author of “ Permian Fossils,” says, to look for 
fossils in this Formation in Europe. That there are now found fishes, shells, and impressions of footsteps, probably 
a Batrachian. That in Germany the Posidonia minuta is stated to pervade the new red system, from the Keuper 
to the Bunter sandstone, inclusive, but in England it is peculiar to the upper Formation, and very abundant in 
some of the beds. p. 338. 
I The genus Loxonema was established by Phillips, for a shell near to Chemnitzia, and belongs to the Family 
Melaniana. It has been found in the Silurian and Permian Formations. 
J This specimen, which my friend Samuel Powel, Esq., submitted to my examination, is the only one, of this 
conglomerate limestone, in which I have been enabled to detect the smallest remains of a mollusc. There are in 
it several fragments of whorls, and only one which has as much as three entire whorls. These present very 
closely the form and size of L. Geinitziana, King, from the Permian of England. The specimen is presented to 
the Academy by Mr. AVilliam Struthers. 
§ The fossil plants, chiefly of the order Felices, which prevail in these slates to such an extent, must have been 
nourished in marshy fens of fresh water. 
