OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
405 
cases, to leaves that are already well known, and that have long ago received appro- 
priate names, which names must be those permanently adopted whenever we ascertain 
the correlation of these disjuncta membra. 
The question of the botanical position of both the above plants remains undecided, and 
I confess I shrink from arriving at a decision in the present state of our knowledge 
respecting them. If I succeed in establishing a connexion between the common Oldham 
plant and the equally common Edraxylon , then, strange as it may appear, the former 
will become an undoubted arborescent fern ; at the same time it has many features of 
affinity with the Lycopodiaceoe that must not be overlooked. On the other hand, the 
Burntisland species looks more Lycopodiaceous than fern-like ; yet it is very different 
from all the other Lycopodiacese of the Carboniferous age with which we are familiar. 
I confess I find an increasing difficulty in distinguishing between the fossil stems of 
Lycopods and of Ferns — a difficulty that increases rather than the reverse the more 
extensive my acquaintance with these fossil forms becomes. These objects differ from 
their diminutive recent allies in so many features of their internal organization, that 
structural differences, of which we avail ourselves amongst the living plants, wholly fail 
to help us in discriminating the fossil ones. Until we obtain more decisive evidence 
respecting the foliage of the two subjects of this memoir, I fear we must locate them 
amongst the miscellaneous objects which Brongniart brings together under the heading 
of “ Sedes incertce 
The two figures Plate XXXI. figs. 48 & 49 are scarcely restorations, because little is 
introduced into either of them the presence of which is not absolutely demonstrated in 
the preceding figures. They are therefore diagrams showing the bird’s-eye view of the 
actual structure of these plants, rather than restorations. The various letters of reference 
attached to them respectively indicate the same structures and tissues as those employed 
in all the other figures. 
I have again to acknowledge my obligations to my Oldham friends, Mr. Butterwortii, 
Mr. Nield, Mr. Whittaker, and Mr. Isaac Earnshaw, for the aid they have afforded me 
in keeping me supplied with an abundance of specimens for examination. Through 
Mr. Xield’s invaluable aid I have obtained large supplies of the calcareous nodules in 
which the fossil plants are found ; and every one of these nodules has been subjected 
to an exhaustive examination, lest any available fact of importance should escape my 
eye. In reference to the Burntisland specimens, all my great obligations are centered 
in George Grieve, Esq., whose persevering energy and kindness I have already 
recorded in previous memoirs, and who has continued to lay me under fresh obligations. 
I must also record kind assistance from the Messrs. Patteson, the well-known marble 
merchants of Manchester, who have allowed me the gratuitous use of their labourers 
and mechanical appliances on several occasions, when such help has been of material 
* More recent researches have rendered it increasingly probable that Heterangium Grievii is a true fern. 
If so, the exhibition in its vascular axis of a very rudimentary form of exogenous growth becomes a physio- 
logical feature of great interest. — Manchester, September 15th, 1873. 
