46 
BRITISH EOCENE FLORA. 
exceptionally well preserved. PI. IX, fig. 2, represents an almost perfect frond (unfor- 
tunately reduced in the engraving to one fourth the natural size), in which there is a 
double forking of the stipes and a tripinnate limb. The pinnae are ovate in general out- 
line, with sessile pinnules, almost decurrent at their base, as in PI. VIII, fig. 1, or more 
rarely, and in the lower part of the pinnse only, shortly stipitate (PI. IX, fig. 2). The 
pinnules vary from broadly to linear lanceolate, and are very acuminate at the apex. The 
margins are coarsely toothed, laciniate- dentate tolobed,the lobes being acute or crenulate. 
The venation, magnified on PI. VIII, figs. 3 and 4, is of the type of Gydopteris simplex 
aqiialis. There is either no midrib, as in the fig. 4 referred to, or it is faintly visible, 
as in fig. 3, and the veins are very slender and close together. No traces of fertile pinnse 
have hitherto been met with. 
The repeated forkings of the stipes and the type of venation point more to the genus 
Anemia than to Asplenium^ as dichotomy is characteristic of the Schizaacea, and similar 
forked branching occurs in Anemia, either in the stipes of the sterile fronds only, or in both 
the fertile and sterile fronds. 
Saporta and Heer do not agree in our determination, and the former has kindly stated 
at some length his reasons for differing : they are, that no known living Anemia has so 
lanceolated and attenuated a form, nor so coriaceous a texture ; and that each segment, 
whether entire or subdivided, is attached directly to the rachis as a pinnule or pinna, and 
is never either decvn-rent or confluent. Anemia, he thinks, is adiantoid in growth, and 
has nothing in common with this Fern. On the other hand, he felt, when he described it 
from Sezanne, extremely doubtful whether it should be placed with Asplenium ; and, these 
doubts being now further confirmed, he has suggested ^ that, since it appears to be an 
extinct form with doubtful affinities, a new genus, perhaps allied to Todea through 
T. barbo.ra, should be formed to receive it. 
Dr. Stur, from an examination of the plates and a small specimen which I forwarded 
to him, believed it to be an Osmunda. We cannot find, however, that any existing 
Osmunda more closely resembles it than 0. regalis, and this seems so unlike in general 
growth that the data for placing it in that genus appear to us insufficient. Neither are 
we able to consider it an Asplenium ; for, although many species of that genus resemble 
it somewhat in their general free growth, cutting, and venation, yet no vestiges of the 
sori, so abundant and persistent on the fronds of Asplenium, have ever been found in any 
locality upon any of the great number of specimens examined. It seems almost certain 
that the fertile pinnse were separate ; and, as we have seen in the similar cases of Chrysodium 
and Osmunda, therefore rarely, if ever, preserved. Notwithstanding that it does not agree 
very closely with any existing species of Anemia, the general form and dichotomy of the 
frond, the venation, the length and strength of the stipes, the separation of the fertile and 
barren pinna3, have, after much consideration, induced us to place it in the genus Anemia. 
In addition to the genera mentioned, it is also not unlike Hiyrsopteris and some 
1 In letter. 
