1914-15.] Fossil Micro-organisms. 123 
The smaller threads measure 2 jm across, and the larger from 4 /x to 5 /x. 
Branching was relatively frequent, and, as in the case of the organism 
described above, the same peculiar swellings were observed, as well as the 
same tendency towards the whorled arrangement (fig. 16). Unfortunately, 
no traces of organs of reproduction were observed. 
It is not impossible that this organism is the same as the one described 
above. In the meantime I propose to follow the suggestion made by 
Mr Seward in his Fossil Plants, and to designate the species Paloeomyces a 
pending further developments. 
A Fossil Actinomyces from the Dunliath Ferruginous 
Limestone : Actinomycites a. 
The rock in which this organism was found was a ferruginous oolitic 
limestone from the Inferior Oolitic Series of the J urassic rocks of the island 
of Skye, N.W. Scotland. A section of the rock is shown in Plate I, fig. 6. 
The oolites were very small, on the average about I mm. long, and em- 
bedded along with them in the calcite matrix were more or less rounded 
particles of animal remains, encrusted, as were all the oolites, with ferric 
hydroxide. One of these particles is well shown at A in Plate II, fig. 6. 
It must be noted that, unlike Phycomycites Frodinghamii, the micro- 
organisms whose remains could be seen inside these animal fragments were 
not iron-organisms, as the iron was confined entirely to the periphery of 
the animal fragment, and was entirely absent from the surfaces of the 
micro-organism inside these fragments. A portion of the animal fragment 
much enlarged is shown in Plate II, fig. 7. The animal remains are 
represented by a few cells, and there were here and there fragments of 
some fungal hyphse, but the bulk of the space is occupied by fragments 
of a micro-organism which was made up of threads of not more than I /u, 
iiwoo iu section. The threads branch freely, and are thickly encrusted 
with some black carbonaceous material, which, not being uniformly laid 
on, gives the thread a very irregular appearance. Examples are given in 
fig. 17. At a first view the assumption that these remains represent those 
of an extinct micro-organism may not seem warranted ; but in parts the 
black overlying material, to the presence of which it doubtless owed its 
preservation, had been torn away as in fig. I7(X, and, wherever this was 
the case, bits of hyphsc thread with a well-defined membrane could be 
clearly seen underneath. Apart from this, the general view shown in 
fig. 7, Plate II, showing a thick meshwork of minute threads inside an 
organic fragment, clearly indicates that some micro-organism had ravaged 
the organic fragment when it was engulfed ; that is to say, what was 
