44 
BRITISH EOCENE ELORA. 
raclii ienui ; _pinms oUongis ; pimiuKs approximatis patentibus, linearihus vel lanceolato- 
ohlongis, margine iniegerrimis vel crenatis ; apice ohtusis ; nervatione Pecopteridis vera ; 
nervo primario e raclii angulo subaciifo, rarius recto exeunte, tenui, plus minusve Jlexuoso ; 
nervis secundariis cum primario angulos acutos formantibus, abbreviatis, catadromis, fur cutis, 
rarius simpKcibiis ; nervis tertiariis catadromis, arcuatis, simplicibm, rarius furcatis, 
injimo lateris exterioris receptaculum pimctiforme emittente. Saris singularibus vel duobus 
rotundis, lobatis. 
Middle Bagshot, Bournemouth. 
The stipes and rachis are slender, and are always found associated with the remains of, 
and sometimes attached to the pinnules The repeatedly dichotomosing character of the 
stem is well seen in the specimen, PI. VI, fig. 8, in which is also shown one of the young 
buds produced at the forking of the larger stipes. The stipites were furnished with short, 
hook-like tendrils. Eigs. 9 and 10 show these tendrils with remains of the rachis, and 
fig. II with the attachment to the stipes only. On this piece and at fig. 8 are spirally 
rolled buds. The relative position of the tendrils and pinnae is shown on PI. X, fig. 2. 
The remains of pinnae, represented in PI. VI, figs. I, 2, 3, and 7, show them to have 
been of an elongated, almost lanceolate shape, bearing linear or lanceolate pinnules of 
unequal length. These are closely set, with crenate or entire margin and rounded apex. 
The venation is that of Pecopteris vera. The midribs of the pinnules are sinuous and 
relatively slender ; they leave the rachis, which is itself slightly flexuous, at angles of 65° 
to 80°, rarely either more acute or obtuse. The secondary veins leave the midrib in cata- 
dromous order at the same angles as those formed by pinna and rachis, and are mostly 
forked, rarely simple. The ternary veins are also catadromous and mostly simple. The 
sori occur on one or both of the exterior venules of each group of veins. The sporangia 
were deciduous, and arranged round a small, oval, punctiform receptacle. There are 
visible six to eight impressions to each cluster, but only the bases of these are seen in 
places where the leaf has chipped off. 
The fossil form is distinguished from all existing Gleichenice by the possession of 
tendrils or hooks, indicating a more pronounced creeping or climbing habit. With this 
exception, however, it bears a close resemblance to two recent species, forming sections 
of the sub-genus Meriensia, G. piectinata and G. dichotoma. The size and form of the 
pinnae, the branched and zigzag stipes, the buds occurring in the forks, the venation, 
and the sori, are all similar. The resemblance is considerably heightened by the very 
unequal lengths of the pinnules, even when side by side, and by the fact that only those 
which are much longer than the rest are regularly crenated, as if the crenations were an 
expression of luxuriant growth. Adiantoid bracts are sometimes developed at the 
forkings, and these, being found associated with the fossil Gleichenia, had been thought 
to indicate the presence of Adiantum. 
G.pectinata, which it the more particularly resembles, is a native of tropical South 
