432 THE MEDALS OF CREATION. Cuap. XI. 
Jigs. 2%, 2". The cavities of these shells are occasionally 
filled with flint, but in general with chalk, which may be 
entirely cleared away, as in jig. 2. The Hippurites of the 
limestone of the Pyrenees are frequently occupied by cal- 
careous spar, and the substance of the shells is occasionally 
transmuted into the same mineral. 
MOLLUSKITE ; OR THE CARBONIZED REMAINS OF THE SOFT 
PARTS OF MOLLUSCA.—Before proceeding to the consideration 
of that numerous and important division of the mollusca 
Eaen. 139: CoPROLITES AND Mon.uskirEe. Chalk and Greensand. 
Fig. 1.—Copnronits of a fish (Macropoma). Chalk, Lewes. 
2.—CopROLITE of a fish (Squalus). Chalk marl, Hamsey. 
3.—Mo.LtuskItE of a Rostellaria. (Mr. Bensted.) Kentish Rag, 
Maidstone, 
the Cephalopoda, I will offer a few remarks on a carbona- 
ceous substance resulting from the gelatinous matter of 
which the soft bodies of these animals are composed, and for 
which I have proposed the name of molluskite, to indicate 
its nature and origin. 
