— 441 — 
These are the lateral walls of the cells, the distal or external walls 
having in most cases been destroyed as a result of bacterial action. 
A dense ground mass of gelatine supports the cells and surrounds 
the internal cavity which is distinctly seen in many of the thalli, 
in both sections (4) 
Bertrand and Renault have reported that the number of cells in 
the young thallus is as great as that in the large one, the increase in 
size of the thallus being accompanied by changes in the individual 
cells. The latter are at first prismatic, but the protoplasmic contents 
gradually assume a pyriform development, the broader end being 
inward. This enlargement of the inner endsof the cells, which form 
asingle layer in the cavity of the thallus, producing more or less 
brain-like convolutions, as is somewhat indistinctly shown in both 
figures. 
The gelatinous remains, which represent the genus Reinschia, 
are regarded by Renault as most closely related to the Hydrodictyacece 
and the Volvocacee. They must have floated in indescribable‘abun- 
‘dance at or near the surface of the water, in which they fell in showers 
to the bottom. The preservation of so great an amount of these thalli 
is probably due to the presence of some antiseptic property, possibly of 
bacterial production, at the bottom of the quiescent area in which they 
generated and fell. 
As in many of the other algal coals and oil shales, the organisms 
appear to have exercized an elective influence on various hydro-carbons, 
including certain combinations of high illuminative value, and accor- 
dingly to have been enriched beyond their original hydro-carbon 
contents. Very little foreign vegetable matter such as spores and other 
debris of higher plants appears in the sections. 
For the sake of comparison, I have shown in fig. 18 a portion 
of the kerozene shale (boghead) from Blue Mountain. in New South 
Wales, cut in a direction nearly vertical to the bedding. Its similarity 
to the corresponding section of the Brazilian boghead will at once be 
observed. I have distinguished the latter as the variety brasiliensis on 
account of the proportionately greater abundance of the large thalli, 
as shown in the illustrations. 
e 
(4) The horizontal section, shown in fig, 12 is unfortunately cut from a portion of 
‘the rock in which thé thalli are slightly more disorganized than in the Tayer ‘tepre- 
sented by the vertical section. 
