SHOWING STRUCTURE, FROM THE RHYNIE CHERT BED, ABERDEENSHIRE. -871 
Permo-Carboniferous period can be extended back to the Early Devonian. There 
is no satisfactory evidence of the existence of Eumycetes, although, in the light 
of the demonstration of septate mycelium, the question of their presence must be 
left to some extent open. 
Since the fungi of the Rhynie peat show only hyphse, vesicles, and resting- 
spores, any exhaustive comparison with other fossil and living forms, would be of 
little value. It is only necessary to make clear some general lines of comparison. 
As already pointed out, these fungi, though more abundant and perfectly pre- 
served, resemble the fungal remains known from Permo-Carboniferous rocks. 
Some of these have had names given to them, while the features of others are 
sufficiently known by descriptions and figures. Attention has been directed by 
a number of investigators to the hyphse and resting-spores found in connection 
with decaying vegetable remains in the coal-balls. The Rhynie fungi are similar 
in general type to these. Thus the groups of spores developed from the intrusive 
mycelium in the large resting-spores of Palaeomyces Gordoni and Palaeomyces 
Gordoni var. major may be compared with the fungal spores filling certain mega- 
spores of Lepidodendron as described by Williamson.* A portion of hypha 
attached to one of the spores of the intrusive fungus is indeed shown in 
Williamson’s drawing.! 
A number of forms of palaeozoic fungi which have been described and named 
by various observers are collected by Meschinelli,^ to whose work it will be 
sufficient for our purposes to refer. Leaving aside more problematical remains, 
the general similarity of the forms described by Meschinelli as Phycomycetes, under 
the names of P alseomy cites gracilis, Palseomycites majus , Peronosporites antiquarius, 
Protomycites protogenes, and Oochytrium Lepidodendy'i, to some of the Old Red 
Sandstone fungi described above will be evident. In particular, we may point out 
the resemblance between the hyphse and vesicles or spores of Peronosporites 
antiquarius and those of Palaeomyces Asteroxyli and Palaeomyces Gordoni ; between 
Palseomycites protogenes and Palaeomyces Gordoni, as regards the double contour 
of the spore ; and between the fine hyphse attached to small spores of Oochytrium 
Lepidodendri and the intrusive mycelium and spores of some of the fungi described 
under No. 14 above. The remains of fine hyphse forming appendages to the spores 
are characteristically similar in the latter case. 
It is not easy, in view of the merely vegetative growth-forms in which the fungi 
of the Rhynie peat occur, to go far in comparing them with existing fungi. As 
already pointed out, it is impossible in the absence of distinctive reproductive organs 
even to refer them to a particular group of the Phycomycetes. The characters of 
the mycelium and resting-spores suggest comparisons with Saprolegniacese, Pythiacese, 
and Peronosporacese. In various forms of these (and in other fungi) the mycelium is 
* Annals of Botany, vol. i (1888), p. 315. t Log. cit., p]. xviii, fig. 15. 
t Fungorum Fossilium Omnium , Iconographia, Vicetiae, mcmii. 
TRANS. ROY. SOC. EDIN., VOL. LII, PART IV (NO. 33). 
134 
