8 Mr. R. Kidston on the Fructification of 
of a single specimen of Sphenopteris delicatula, Sternberg*, 
which appears, however, rather to be a small variety of Z. 
tenella than a distinct species, as they are connected by inter- 
mediate forms. This circumstance appears to prove conclu- 
sively that ‘the fructifying fronds can only belong to £. 
tenella. 
All the fruiting fronds of this fern with which I have met 
were collected by myself at Furnace Bank, Sauchie, near Alloa, 
where it occurs very plentifully, but is limited to a single bed 
of arenaceous shale overlying the coal, which is at present 
being worked. 
Figs. 1 and 2 show two of the most common types of this 
plant as met with at Sauchie. Brongniart’s figure represents 
only a small portion of a frond; a much better specimen is 
shown in the ‘Illustrations of Fossil Plants ;’ but it is there 
only designated “‘ Sphenopteris sp.” 
Eusphenopteris tenella must have attained considerable size, 
as one of my specimens shows pinne 7 inches long, given off 
from an axis only the eighth of an inch thick. Of the barren 
fronds, some are lax and others much more compact ; we have 
in the fertile fronds similar distinctions. ‘This is shown in 
figs. 3 and 4. The capsules or urceolate indusiums are oval 
in form, and show a small depression at their apex, which 
probably indicates the position of an aperture (figs. 3 
and 4). Their greatest length measures 3, of an inch. 
They are arranged in two rows, one on each side of the rachis 
of the pinnule, the capsules being alternate, as shown in figs. 
4 and 6; but they commonly appear as secund, the one row 
being bent over the other. ‘This is well shown in fig. 3. 
The different positions of the capsules are probably dependent 
upon their state of ripeness when fossilization took place. 
From the fine state in which the specimens are preserved, the 
outline of the cells composing the capsules is distinctly 
shown. , 
The affinities of this fern to recent genera are somewhat 
obscure. ‘The capsules in form resemble those of Hymeno- 
stachys (Hymenophyllacee) ; but in the fossils there is no 
discernible trace of a column, which forms a constant character 
in that genus. ‘They agree, however, in the dimorphic con- 
dition of the fronds. I fear that at present we can only pre- 
sume that this fern is most probably referable to the Hymeno- 
pees Both fertile and barren fronds are plentiful in the 
oal-measures, Sauchie, near Alloa; and a fine barren speci- 
* ‘Essai d’un Exposé Geognostico-Botanique,’ Sternberg, pl. 26, 
fie. 5. 
