1914 - 15. 1 
Fossil Micro-organisms. 
133 
DESCRIPTION OF PLATES. 
Plate I. 
Fig. 1, X 800. Hyphse of Phycomycites Frodinghamii (Ellis). Photographed 
from section of Frodingham Ironstone. Hyphae were enclosed in fossilised organic 
fragments, and encrusted with ferric oxide. Frodingham Ironstone belongs to the 
upper part of the Lower Lias, a, Hypha. 
Fig. 2, X 250. Phycomycites Frodinghamii (Ellis). Interior of fossilised organic 
fragment in Frodingham Ironstone. Shows hyphse and also a good specimen of those 
irregular swellings that are characteristic of this organism, a, Swellings on hypha ; 
h, at this point a branch hypha arises ; c, hyphee scattered in matrix. 
Fig. 3, X 250. Phycomycites Frodinghamii (Ellis). Interior of fossilised organic 
fragment in Frodingham Ironstone, a, A sporangium-bearing hypha ; 6, mature 
sporangium ; c, young sporangium. 
Fig. 4, X 250. Two sporangia of Phycomycites Frodinghamii. Interior of 
fossilised organic fragment in Frodingham Ironstone. In the sporangium to the 
right in the figure, 6, a spore, a, is seen partially extended from the sporangium. 
The sporangium was evidently crushed during the process of preparation of the 
slide with the result that one of its four spores had become exposed. 
Plate II. 
Fig. 5, X 250. Section of calcareous oolitic stone from island of Raasay (N.W. 
Scotland). Shows fragment of organic remains which had been ravaged by the 
attacks of a fungus. Fungus is provisionally named Paleeomyces a. a, Hyphse ; 
h, remains of host. 
Fig. 6, X 27. Dunliath ferruginous limestone. a is an organic fragment 
which, unlike the neighbouring oolites, is only incompletely rounded. This fragment 
is full of the remains of a small micro-organism. For details see text. Organism 
is named Actinomyces a. 
Fig. 7. Dunliath ferruginous limestone. Shows the spot marked a in fig. 6 
magnified 250 times, so as to render visible the hyphse of the micro-organism which 
has been named Actinomyces a. The hyphse are the small dark short lines which 
relieve the whiteness of the central part of the photograph. 1, Calcite matrix ; 
2, remains of animal cells ; 3, other hyphse not further investigated. 
Fig. 8. Section of a nodule from the base of the Gault (Folkestone). x 400. 
In section the stone is seen to be cellular in composition, the cells being very 
minute. The walls of the cells are reddish brown, due to the large percentage of 
ferric oxide. The cavities of the cells are very minute and are in the majority of 
cases filled with air. In some, however, as in the plate shown, the cavity was filled 
with organic fragments. The bacteria are found in the latter, a, Walls; b, cavity 
filled with organic fragment. The rods pointing in all directions are the remains 
of the bacteria which lived in the organic remains. Organic fragments of all sizes 
are common throughout the nodule. 
{Issued separately April 27, 1915.) 
