132 Reports and Proceedings. 
from the Fen specimens to the recent. A question was raised as to 
whether Castor Europeus had ever been obtained from the Forest- 
bed. ‘The smaller specimens might probably belong to younger and 
not full-grown Trogontheria. The greater proportionate size of the 
posterior molar tooth in the lower jaw of Trogontherium was pointed 
out by Mr. Gunn as a mark of difference from Castor Europeus. 
It is remarkable that in the Bacton specimen (a cast of which was 
_ presented to the Norwich Museum by the Rey. S. W. King., F.G.S., 
of Saxlingham Rectory), and in every other already described 
specimen, this tooth is missing. It is less firmly fixed in the jaw 
than the other molars; and in Mr. Gunn’s specimen it had been 
loose and had dropped out since it had come into his possession. ‘This 
may be regarded as a satisfactory proof of the correct view of 
Professor Owen with respect to the difference between T'vogon- 
therium and Castor Europeus; and M. Lartet is not correct in 
stating, ‘in a note to ‘Cavernes du Périgord’ (page 21), that Palzon- 
tologists have not made any distinction between the two. The atten- 
tion of the members of the Society was specially directed to 
the collecting of these interesting remains. 
A paper was then read by Mr. A. W. Morant, F.G.S., on the 
Formation of Flint in Chalk. We had, in the first instance, com- 
piled, for his own information, all that had been written by the best 
authorities on the subject, and it had occurred to him that the 
compilation miglit be useful and acceptable to the members of the 
Society (as it certainly was). The subject is one of great interest, 
and was well discussed. As an illustration of the theory of segrega- 
tion of the siliceous particles from the calcareous mud, Mr. Bayfield 
stated that in the manufacture of pottery; where the pounded 
calcined flints are mixed with pipe-clay into a plastic mass, if the 
latter be allowed to stand a few days, the silica will be aggregated 
into nodules. Mr. Braidman stated that under a temperature 
exhibiting a pressure of sixty pounds, in an alkaline solution, flint 
became perfectly soluble. Mr. ‘Taylor showed that the silica dissolved ° 
in sea-water, therefore, is the storehouse whence the Diatomacez 
obtain their supply, whilst their shields, accumulating on the ocean- 
bottom, would form nodules and bands as in the case of the Chalk- 
formation._—J. T. & T. G. B. 
BristoL NaTuRALISts’ Society.—I. December 7th, 1864.—At 
the Thirty-second Ordinary Monthly Meeting, Mr. W. Sanders, 
President, in the chair, the Secretary announced the election of eight 
new members, and brought forward a resolution of the Council 
relative to the formation of a Scientific Library by Voluntary 
Subscription. Mr. D. Davis read a paper On the Natural History 
of the Inhabitants of the British Isles. 
Il. Geological Section, Nov. 25th.—Mr. W. Sanders in the chair. 
It was resolved that the day of meeting be altered from the fourth 
Friday to the fourth Thursday in the month. An indiscriminate 
series of fossils from rocks below the Devonian were placed upon the 
table for examination, and the President proposed that each evening 
