EOCENE EERNS. 



71 



the pinna described as Phegopteris prce-cuspidata to be identical with Goniopteris stiriaca, 

 which I now think probable, and setting aside Pteris {?) Hookeri (Heer. sp.), which 

 may be but the drawing of the enlarged lateral pinna of Pteris eoccenica. It is very- 

 remarkable that of all these only one is found passing either into the Lower Bagshot or 

 the Upper Eocene. Only three species are met with in the older beds at Bournemouth, 

 six are added in the middle beds, five of which disappear in the upper beds and are 

 replaced by three others. 



It appears as if we had now a nearly complete knowledge of at least the Ferns of the 

 Bournemouth stage, whose stations were woodland or marsh, for, though work during the 

 past two years has multiplied, and in some cases produced finer specimens, no new type 

 has been brought to light. This concluding part of the monograph on ' British Eocene 

 Eerns,' though enabling several corrections to be made, only adds one species, and this, 

 not because it has been newly discovered, but in view of the extreme probability that the 

 Scotch and Irish Tertiary plants are of Eocene age. 



We are able, in addition, to figure some more perfect and larger specimens of 

 Osmunda, Plate XIII, figs. 1, 2, 3, 4, a dwarf frond of Lygodium (fig. 8) from the 

 same, and a specimen of Goniopteris Bunburii (fig. 7) from Lough Neagh. 



The Ferns already published furnish data of considerable value, and indicate how 

 much we may expect to learn from the remainder of the flora. Among them, three are 

 peculiarly important through the ease with which they can be identified, for each is scarcely 

 distinguishable from an existing and widely distributed species, yet like no other in the 

 world. There is thus absolutely no shade of doubt about either the authenticity of their 

 determination or tlie close relationship they bear to a sharply defined existing species. 

 No more definite data could well be imagined, and it may be instructive, even at this 

 early stage, to reflect upon what these and other Ferns teach, before commencing a new 

 subject. One of these cannot be separated by any specific character from the existing 

 Clirysodium aureum, a magnificent plant with dark glossy foliage, inhabiting preferably 

 swampy places, and almost confined to tropical or sub-tropical regions. A description 

 by Moselj^ of its growth in Bermuda reads like a restoration of the Eocene period at 

 Bournemouth. " The most refreshing and beautiful vegetation in Bermuda is that 

 growing in the marshes and caves. The marshes or peat bogs lie in the inland hollows 

 between two ranges of hills. These bogs are covered with a tall, luxuriant growth of 

 Ferns, especially two species of Osmunda (0. cinnanmnea and 0. regalis). Some Ferns 

 are restricted to particular marshes. In some Acrostichmi aureum grows^ densely to a 

 height of from four to five feet. Together with the Ferns grow the juniper, which 

 thrives in the marshes, and a palmetto, which gives a pleasing variety to the foliage,'' 



The species seems to have arrived with the sudden increase of temperature apparent 

 in the London Clay period, for its pinnse are massed together in the Lower Bagshot at 



1 ' A Naturalist on the Challenger,' p, 23. 



2 A name preferred to Chrysodium, in Hooker's ' Synopsis Filicum." 



