Geological Society of London. B17 
Durham was given, since the first discovery of salt by Messrs. 
Bolckow, Vaughan & Co. at Middlesboro’, in the year 1859. 
The stratigraphical position of the saliferous rocks of the Durham 
salt-district was considered in some detail. The diverse views which 
have been previously expressed on this head were referred to, and 
reasons given for concluding that all the beds of rock-salt which 
have been hitherto proved in this field, and the red rocks with which 
they are associated, belong to the upper portion of the Trias, viz. 
to the Upper Keuper series (Waterstones subdivision). 
The probable area of this salt-field, the limits of the distribution 
and varying depths of the chief bed of rock-salt, were indicated, and 
the extent of its supplies pointed out. 
In conclusion, the author called attention to the waste, as well as 
to certain other disadvantages resulting from the process of winning 
the salt now in operation. 
5. “On the Occurrence of Calcisphere, Williamson, in the 
Carboniferous Limestone of Gloucestershire.” By E. Wethered, 
Esq., F.G.S., F.C.S. 
The small hollow spheres, with varying forms of peripheral 
appendages, described by Prof. Williamson as Calecisphare, were 
found in the Carboniferous Limestone of Flintshire, and were 
suggested by him to be possibly Foraminifera or the reproductive 
capsules of some marine form of vegetation, although he admitted 
that no forms hitherto discovered afforded any definite support to 
this hypothesis. Prof. Judd expressed a belief that the objects 
were Radiolaria; whilst Mr. Shrubsole discovered similar bodies in 
the Mountain Limestone near Llangollen, and conjectured that the 
described forms included both Foraminifera and Radiolaria. 
The author has discovered the Calcisphere in great numbers in 
the Carboniferous Limestone of Gloucestershire. He discussed the 
identity of certain calcareous rings ‘005 in. in diameter, seen in 
sections of the limestone of Clifton, etc., with siliceous bodies which 
he had described in a recent paper read before the Society, and gave 
an account of the calcareous and siliceous forms which were both 
referable to Calcisphere. He commented upon the character of the 
carbonate of lime of the calcareous bodies, which presented a granular 
structure characteristic of the truly organic portion of the limestone, 
and not a clear crystalline aspect like that of the infilling or re- 
placing calcite; he concluded therefore that the tests had been 
originally calcareous, and not siliceous replaced subsequently by 
carbonate of lime. This was urged as a strong argument against 
regarding the organisms as Radiolaria, and the author, whilst 
considering it unwise to come to a decided conclusion, believed it 
safe to say that they were Protozoa. 
6. “Second Note on the Movement of Scree-material.” By C. 
Davison, Esq., M.A. Communicated by Prof. T. G. Bonney, D.Sc., 
F.R.S., F.G.S. 
After briefly recapitulating the substance of his previous paper, 
the author now communicated the results of experiments continued 
for a year. He gave a figure in which a continuous line represented, 
