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 pinnse 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 pinnae 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 to lobed, the lobes being acute or crenulate. 

 The venation, magnified on PI. VIII, figs. 3 and 4, is of the type of Ct/clopteris simplex 

 (Eqiialis. 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 pinnae 

 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 Schizaacece, 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 Pleer 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 decin'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. barhara, 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 Osmiinda. We cannot find, however, that any existing 

 Osviunda more closely resembles it than 0. recalls, 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 AspAenium ; 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 pinna? 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 pinnae, have, after much consideration, induced us to place it in the genus Anemia. 



In addition to the genera mentioned, it is also not unlike Thyrsopteris and some 



^ In letter. 



