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with a large number of sponge spicules and some Radiolaria. The rock is 
permeated with silica in the amorphous and globular colloid state as well 
as in the chalcedonic form. As usual, it has filled the foraminiferal cells, 
though their silicification does not seem so complete as in some examples. 
The residue after the action of acid consisted of sponge spicules and the 
white granular material, which, as before, clung to the spicules. 
C 6. — A small fragment of grey-coloured chalk. It consists almost 
entirely of spheres and cells, all large in size and bold in outline ; they form 
about 65 per cent, of the rock. With these are numerous bodies of the 
same size, slightly elliptical in shape. One end is, however, abruptly 
truncated, thus giving the organism the shape of a horse-shoe. Were it 
not for the abundance of these forms, one would consider them to be broken 
cells or spheres, but their number suggests an organism not yet recognised. 
I find similar bodies occur in the lower part of the Middle Chalk of England, 
but they are comparatively rare. From optical observation the matrix 
seems to contain terrigenous material. I can detect quartz mica and, I 
think, chlorite in the section, but the grains are very small. I did not see 
the original specimen ; the section was sent me by Mr Earland already 
mounted, but a small fragment believed to be the same material was 
included. On treatment with acid the finer part of the terrigenous material 
in this was found to consist of lath-shaped particles. The fragment was 
too small to analyse. 
The phenomena exhibited by the Belhelvie specimens are such as we 
should expect to find in dealing with a group of rocks laid down during 
a period of gradual submergence; and with this fact in mind, though we 
have no fossils to guide us, it seems possible to follow a sequence of events 
in their sedimentation and to roughly arrange the boulders in some sort 
of order. 
The friable green-grey rock is a purely terrigenous deposit containing 
much glauconite, and it may be compared with the glauconite sands which 
are found almost everywhere in the British Islands at the base of true 
chalk. The presence of Radiolaria, its mineral grains and the lath-shaped 
form of its finer particles, link it up with the other boulders of the series, 
and I think it may fairly be regarded as a fragment of the basal bed. 
Both sand and glauconite grains are of small size — facts which seem to 
indicate that it was laid down at some distance from land and away from 
the influence of strong mud-bearing currents. 
The marl of B I, viewed as a thin section, would hardly be taken as 
a member of the Cretaceous series, for practically all organisms are 
