EOCENE FERNS. 



49 



bearing fronds of such unequal size, and so variable that the number and angle of 

 divergence of the lobes differ strikingly in the same plant, while the primary veins may 

 also be either excurrent or merged, free to the base or united. If the Swiss species are 

 united, it is seen that the British form differs from them in having, on the average, 

 considerably larger and longer, slightly undulating lobes. It also bore simple fronds, 

 none of which have been met with in the latter. The lobes in the former always 

 diverge at acute angles, whilst in the latter they frequently diverge at obtuse angles. In 

 the British form the venation is more pronounced and the veins more crowded together. 

 Count Saporta has met with one of these, L. Gaudini, in the Upper Oligocene of Cereste, 

 and has again found that the fertile fronds are identical with those of Bournemouth. 

 Another very similar form has been described in De Bey and Ettingshausen's ' Kreide- 

 Flora von Aachen,' from mere fragments. Lesquereux, in the ' U.S. Geol. Survey of the 

 Territories,' vol. vii, 1878, describes three other species, two of which, however, appear to 

 us to have been founded on scarcely sufficient material. 



Among recent species, L. palmatim, inhabiting Florida to Massachusets, bears the 

 closest resemblance to L. Kaulfussi, especially in the form of the fertile fronds. The 

 barren fronds of the fossil were much larger, and tapered to the base ; yet no other 

 existing Lygodium has such a thin and sinuous mid-rib, nor precisely the same form of 

 fertile frond. It is remarkable, as Saporta has pointed out,^ that all the fossil Lygodia 

 yet described are referable to the section of the genus now represented by the single 

 species L. palmatim . 



L. Kaulfussi is found sparingly at Bournemouth, associated with dicotyledonous 

 leaves of forest trees ; more rarely in company with other Fern remains. It is occasion- 

 ally found in the leaf-beds under the High Cliff Hotel, but more generally in the beds at 

 the western termination of the Bournemouth Cliffs, near Poole Harbour. The bases of 

 the fronds are seldom preserved either in this or the Miocene form, whilst the ends of 

 the lobes are constantly doubled over, as if they were of soft consistence and could not 

 withstand maceration. The fertile fronds have not been met with associated with the 

 barren fronds, but were found under the High Cliff Mansions by Mr. A. Baldry, junior, 

 to whom we are indebted for the opportunity of figuring them. 



(h) OsmundacecE. 

 OsMUNDA LiGNiTUM, Giebel (sp.). Plate IV, figs. 1 — 3. 



PeCOPTEUIS LIGNITUM, P. CRASSINEUVIS, P. LEUCOPETRiE, P. ANGUSTA, Giebel. Zeit- 



schrift fiir die gesammten Naturwissenscbat'ten, vol. x, 

 pp. 303—307, pi, ii, 1857. 



1 In letter. 



