72 
S'! 
patches of a substance apparently identical with what the 
late Dr. Mantell designated Molluskite, and which he 
believed to be the remains of the soft animal substance of 
marine organisms. In many of these patches the Foramini- 
ferous shells are better preserved than is the case with the 
rest of the matrix enclosing the large fossil shell. It appears 
as if this Molluskite had partially protected the calcareous 
Foraminiferafrom the solvent action which had disintegrated 
most of those forming the rest of the deposit. 
But the most interesting features of the specimen are 
seen within the chambers of the Nautiloid shell. The Fora- 
miniferous ooze has entered freely through the large, open 
mouth of the terminal chamber in which the animal resided 
and filled the entire cavity of that chamber. There is no 
doubt whatever as to the original identity in the character 
of the ooze thus enclosed within the shell and that which 
constitutes its investing matrix, though they now appear 
very different. The latter portion was freely permeated by 
water containing the solvent carbonic acid; hence the more 
or less complete disintegration of its Foraminiferous shells. 
But in the limestone enclosed within the large terminal cham- 
ber of the Nautiloid shell, almost every Foraminifer is pre- 
served in the most exquisite perfection. This is especially 
the case in the deeper part of the chamber, most remote 
from the mouth, as also in the instances of one or two of 
the rmre internal closed chambers, into which the mud 
has obtained entrance through small accidental fractures in 
the outer shellwall. It appears obvious to me that the 
thick calcareous shell of the Nautilus has protected the 
enclosed shells of the Foraminifera from the action of the 
