276 Proceedings of the Royal Society of Edinburgh. [Sess. 
large pieces of Inoceramus shell, these being embedded in the calcareous 
matrix above described. 
The chalk can hardly be called nodular, but I can only conceive this 
peculiar structure to have been formed by lumps of partly consolidated 
wet chalk being rolled lightly over sand made up of the above-mentioned 
materials. The chalk broke down quickly in acid, but a large part of the 
heavy matter removed by levigation consisted of small masses of the 
white granular material. Though no spicules or Radiolarians can be seen 
in the sections, they were numerous in the acid residue, the Radiolarians 
having the mesh-work of their tests and delicate spines well preserved. 
Silica had infilled a large number of the “spheres” and cells, casts in 
silica being very numerous. It will be seen from the table that the sand 
grains in the coarse residue are exceptionally large, the maximum size 
being '78 mm. and the average T8 mm. 
B 3, B 5, B 9, B 11. — These specimens when seen in thin sections re- 
semble each other in containing the same kind of calcareous organisms, 
though there is a little variation in their relative abundance. The presence 
of many Globigerinm and Textularians of small size, with some cells and 
spheres, is a feature common to all, and in all are sponge spicules and 
Radiolarians. The heavy residue of B 3 contained a large quantity of 
white granular material, but the amount in the others was insignificant. 
The heavy residues of B 5, B 9, and B 11 consisted chiefly of spicules, casts 
of foraminiferal cells, etc., and mineral grains. All contained Radiolarians, 
usually well preserved, those of B 11 especially so. The siliceous organisms 
as a whole were destroyed in heated caustic potash, but a few spicules 
and casts of Radiolaria in chalcedony occur not infrequently in these and 
other residues. 
Of the other specimens, A 4, with a residue of 2'93 per cent., deserves 
mention. This is a large flattened ice-scratched boulder of hard greyish- 
white chalk. The rock consists chiefly of amorphous calcareous matter in 
which a few Foraminifera, shell fragments, and spheres and cells are out- 
lined. More than a third of the heavy residue consisted of’sponge spicules ; 
mineral grains form the bulk of the remainder. These were larger and 
coarser than in many of the other specimens. The residue contained also 
seven species of Radiolaria, their tests being in a remarkably good state of 
preservation. None of the white granular material was separated in the 
heavy residue. 
A 1, B 4, and B 10 may be considered together. The matrix of these 
specimens is crowded with “ spheres ” ; there are few Globigerinae or other 
Foraminifera, while fragments of Inoceramus shell, sometimes rather large 
