340 
THE GEOLOaiST. 
kind." The remark last quoted bears directly on the point noticed 
in the ragstone hassock in my quarry. 
In the grey Shanklin sand these nodules abound in some localities. 
I have observed them in Sussex, in Surrey, in the Isle of Wight, 
near Yentnor, and in many parts of Kent. In vol. iv. (p. 35) of the 
Geological Society's Proceedings, Dr. Mantell writes, " Mr. Bensted 
having long paid attention to this subject, submitted to my inspec- 
tion several specimens of Bostellaria, Trigonia, and other shells, the 
cavities of vi'hich were filled with a dark-brown substance, in many 
respects identical with the nodular and irregular concretions of 
coprolitic matter which abound in the surrounding sandstone. At 
the same time, Mr. Bensted expressed his conviction that the car- 
bonaceous substance was derived from the soft bodies of the mollusca, 
and that the concretionary and amorphous portions of the same 
matter dispersed throughout the sandstone of the bed were fossilized 
masses of the soft bodies of the animals disengaged from their shells, 
and which had floated in the sea until enveloped in the sand and 
mud which is now converted into the sandstone called the Kentish 
Kag. The evidence collected by Mr. Bensted appears to me so con- 
clusive and so confirmatory of the opinions previously stated, that 
I beg to place before the Society the following abstract of his corre- 
spondence with me upon the subject : — ' The bed of Kentish Eag in 
my quarry, which lies immediately beneath the stratum that contained 
the remains of the Iguanodon, abounds in the usual shells of the 
Lower Greensand, but moue particularly in Trigonise (generally T, 
alceformis), and there is an abundance of a dark-brown coprolitic- 
looking substance, of which I send specimens. 
" ' In some instances this material actually forms the entire casts of 
the univalves and bivalves, and I think there can be no doubt that it 
is derived from the soft bodies of the animals which inhabited the 
shells found in connection with it fossilized in this peculiar manner. 
There are many examples which look more like true coprolites of 
fishes, and some of them contain shells partly crushed, as if they had 
been the undigested contents of the intestinal canal. I am therefore 
inclined to think that the dark material which now occupies the 
shells was the soft body of the mollusk ; that those masses of a con- 
cretionary form which are embedded in the stone are coprolites ; and 
that the shapeless portions of this substance distributed in the rock 
have originated from floating masses of the bodies of the dead shell- 
fish. In illustration of the manner in which such an accumulation 
of materials as I find in my quarry may have been formed, I beg to 
call your attention to the following extract from the American Jour- 
nal of Science : — " One of the most curious phenomena of the year 
183(3 has been the fatal efi'ect of an epidemic disease among the mol- 
luscous animals or shell-fish of the Muskingum Hiver, Ohio. It com- 
menced in April and continued until June, destroying millions of 
that quiet retiring race which peoples the bed of stream.s. As the 
animal died the valves of the shell opened, and decomposition com- 
mencing, the muscular adhesions gave way, and the fleshy portion 
