246 Dr. Mantell’s Notice of Molluskite. 
~ would seem that this stratum had constituted a bank of drifted 
wood and shells, presenting a very analogous condition to the 
phenomena above described. ‘The gelatinous bodies of the 'Tri- 
goniz, Gervilliz, Ostreze, Rostellaric, &c. detached from their 
shells may have been intermingled with the drift wood, in a sand 
bank, while in some instances the animal matter would remain 
in the shells, and become fossilized in the state observable in the 
accompanying examples.” 
The above remarks present a correct view of the circumstances 
under which the phenomena referred to occur in the quarry of 
Mr. Beusted. 
Some of the dark substances extracted from a Trigonia, was 
submitted by my friend, the Rev. J. B. Reade, to a careful anal- 
ysis by Mr. Rigg, who obligingly favored me with the following 
note: “My analysis confirms your suspicion respecting the pres- 
ence of animal carbon in the substance which you sent for ex- 
amination. After removing the lime, &c. by means of dilute 
hydrochloric acid from ten grains of the darker portion of the 
stone, there remained 1.2 grains of dark powder, which gave by 
analysis with oxide of copper .16 of a cubic inch of carbonic acid, 
and apparently a small portion of nitrogen. On subjecting to the 
same kind of analysis two grains of the darker body without 
previously acting upon it by any acid, .054 of a cubic inch of 
carbonic acid was obtained ; so that from these results there is no 
doubt but the darker portion of these substances contains about 
.35 per cent. of its weight of carbon in an organized state.” 
The presence of animal carbon in fossil remains will, I expect, 
be found of frequent occurrence, not only enclosed in the shells 
of mollusca, but disseminated in the surrounding matrix. In the 
unique specimen of a fossil fox from Ruingen, which I had the 
pleasure of dissecting for our distinguished president, I found a 
considerable quantity of carbonaceous coprolitic matter within 
the abdominal region, and I have frequently detected its presence 
in the grit and sandstone of Tilgate Forest associated with the 
bones of reptiles. The black material which is so commonly 
seen to occupy some of the spiral cavities of the Paludina com- 
posing the Sussex and Purbeck marbles, and which by its con- 
trast with the white calcareous spar, adds considerably to the 
beauty of those fresh-water limestones, contains a large propor- 
tion of animal carbon, doubtless derived from the soft parts of 
