224 Proceedings of the Royal Physweal Society. 
The only Sigillaria occurring in this series is the S. Taylort, 
Carr. sp., which, however, is comparatively common,—espe- 
cially in the oil shales. From the cement-stone group two 
species of Lycopodites—L. Vanuxemi, Gopp. sp., and L. Stockit, 
Kidston, have also been got. 
The Calciferous sandstones have yielded four species of 
Bythotrephis, which have not yet been found elsewhere, and 
one of Ptilophyton—P. plumula, Dawson. 
The Calciferous Sandstone Series therefore possesses a 
distinctive flora, which, though allied to that of the overlying 
Carboniferous Limestone Series, possesses individual features, 
which admit of its easy separation from the latter series. 
II. CARBONIFEROUS LIMESTONE SERIES. 
This series is distinguished by its fossil plants from the 
underlying Calciferous Sandstone Series,—as much by the 
absence of many species that occur in the underlying rocks 
as by the presence of a number of plants characteristic of 
itself. 
Notwithstanding the great development of coal in the 
Carboniferous Limestone Series, fossil plants are much more 
rare than in the Calciferous Sandstone Series. 
Again, in the Carboniferous Limestone Series, the prevailing 
plant is Lepidodendron Velthermianum, Sternb.; Sigillaria 
Taylori, Carr. sp., also occurs, but more rarely. From it 
has been got the only specimen of a ribbed Sigillaria— 
S. Youngiana, Kidston—which has yet been met with in 
British Lower Carboniferous rocks. 
The Carboniferous Limestone Series contains some beds 
composed almost entirely of the curious Alga, Spirophyton 
Cauda-galli, Vanuxem sp., entangled among whose fronds 
are found joints of encrinites. . 
Among the ferns Sphen. Dicksonioides, Gipp., Sphen. Linki, 
 Gépp. sp., Sphen. Haueri, Stur, Sphen. Gersdorfii, Gopp. sp., 
Adiantides Machanekii, Stur, and Archeopteris Tschermakz, 
Stur, appear to be peculiar to this group. 
Volkmannia Morristit, Hooker, has also only been found 
in these rocks. 
a 
ee ee 
