302 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [ Mar. 9, 
fossil. No botanist dealing with living plants would venture on such 
materials to decide on their place, far less to describe them as forming 
a new species. It is very different with fossils belonging to the 
animal kingdom, where the portion of the organism preserved is 
generally that which is employed to a greater or less extent in the 
classification of recent forms. I must therefore adhere to the system 
of nomenclature I have hitherto followed, notwithstanding that it 
has been censured by so distinguished a botanist as Prof. Heer (Flora 
Foss. Arct. p. 84), and consider this a species of Osmundites. It 
is no answer to this method to say that species of plants now living 
found in quaternary deposits, being so far fossil, ought to receive 
another name; for if the materials are sufficient to determine with 
certainty the specific identity of the two plants, of course, on the 
principle I adopt, the same name must be applied to both. It still 
seems to me of great importance to be able to distinguish the ex- 
tinct from the existing species by the name, inasmuch as this di- 
stinction conveys also to the student, to some extent, the value of 
the evidence on which the species has been established. 
The fossil has been a larger plant than our recent Osmunda 
regalis, or than a similar stem found in a mass of “ Siisswas- 
serquarz” near Schemnitz, figured by Pettko under the name 
Asterochlena schemniciensis in Haidinger’s Abhandl. vol. 11. (1850) 
p. 163, pl. xx.,.but afterwards referred by Unger to Osmundites 
(Denkschr. d. K. K. Akad. d. Wiss. vol. vi. (1853). I propose to as- 
sociate with it the name of George Dowker, Esq., F.G.S., from whom 
I received the specimen, and to name it Osmundites Dowkeri. It 
was found on the shore at Herne Bay, and could have been obtained 
only fromthe Lower Eocene beds there—perhaps from the beds 
below the London Clay. 
A group of fern stems are found in the later Paleozoic and in the 
earlier Mesozoic strata which are nearly allied to those of Osmunda. 
They have been, unnecessarily, divided into several genera; but as 
they all agree in having a slender caudex covered by the long 
ascending and permanent bases of the petioles, and numerous aérial 
roots, it seems better to unite them under Corda’s genus Chelepteris. 
The materials are not sufficient to determine with any thing like pre- 
cision the position of this group of stems; but in the characters I 
have just given they agree with the recent Osmundacew, as well as 
in haying the vascular bundle of their petioles simple. There is at 
least a fair presumption that this is their position; yet it must be 
‘remembered that these characters are not peculiar to this recent 
tribe, but that they are found also in ferns widely separated from 
them in a natural classification, as, for instance, in Dicksonia ant- 
arctica. The genus Chelepteris, extended as I propose, would include 
the following species :— 
From the Permian of Russia (Grés cuivreux of Orenbourg) :— 
Thamnopteris Schlechtendalii, Brongn. Tabl. Genr. Foss. p. 36. 
Bathypteris rhomboidea, Kichw. Leth. Ross. vol. i. p. 96. 
Anomorrhea Fischeri, Kichw. Leth. Ross. vol. i. p. 102. 
Chelepteris gracilis, Eichw. Leth. Ross. vol. i. p. 98. 
