EOCENE EERNS. 
53 
perhaps, to preserve any distinct form if fossil. O.javanica ranges from Kamschatka to 
Java and Ceylon, and is described by the Rev. C. P. Parish as a magnificent plant, 
similar to Cycas in growth.^ 
OsMUNDiTES DowKERi, Carruthers. 
OsMUNDiTES DowKEEi, CarrutJiers. Quart. Journ. Geol. Soc, vol. xxvi, p. 349, pis. 
xxiv, XXV, 1870. 
— — — Geol. Mag., vol. ix, p. 52, 1872. 
Thanet Sands, Kent. 
This species is based upon a portion of a stem found at Heme Bay, and is admitted 
to have been derived from the Thanet Sands. The whole of the tissues are replaced by 
silica, so that the cells and vessels, and even the starch granules, v^^hich abound in the 
parenchyma of Ferns, are exquisitely preserved. The structure, minutely described by 
Mr. Carruthers, is seen to agree with similar portions of the stem of 0. regalis, which are 
figured by him for comparison. The fossil has been a larger plant than our recent 
0. reyalis. In discussing the paper Mr. Etheridge mentioned the discovery of fossil Eern 
stems of somewhat similar character at Bromsgrove. 
Pteris (?) Prestwiohii, Ett. and Gard. Plate X, fig. 8. 
P. pinnis elongatis lanceolato-linearibus, margine integerrimis, nervatione Neuro- 
pteridis acrostichacea, nervoprimario prominente, apicem versus sensim attenuato ; nervis 
secundariis sub angulis acutis orientibus, valde ctpproximatis, bi- vel trifurcatis, r arras inter 
se parallelis, cum nervo priniario angulum acutum formantibus. 
Woolwich and Reading Beds, Counter Hill, near Lewisham. 
Our illustration is copied from that given by Professor Prestwich in the ' Quart. 
Journ. Geol. Soc.,' vol. x, p. 156, pi. iii, fig. 6. We have not been able to ascertain 
that any of the original specimens are now preserved. Prestwich describes it as " one of 
the recent discoveries by the Rev. Mr. De la Condamine at Counter Hill. This Eern is 
probably an Asplenium ; the leaflets occur in some numbers, and are associated with 
fragments of monocotyledonous leaves, . . . and one or more dicotyledonous 
leaves " (p. 156). 
There is no particular reason to suppose it to be a Pteris ; but in the absence of 
contradictory generic characters we have thought it convenient to consider it as belonging 
^ See a sketch in the Kew Herbarium. 
