FLOOR.] 
FOSSILS. 
41 
4. Eocene Tertiary, or London Clay and Paris Basin (Cases 4, 5 
and 8), Room VI. Not any of these can be certainly identified with 
living Shells; and the species which they most resemble are now 
found at the Cape of Good Hope, the western coast of South America, 
and other localities remote from those where the fossils have been found. 
SHELLS OF THE SECONDARY STRATA. (RoomS V. & VI.) 
5. Chalk, Gault, and Green-sand (Cretaceous System). (Table 
Cases 1 and 2, Room Y.) The characteristic Shells of the Chalk are 
Inocerand, related to the recent Pearl-oyster ; Spondyli ; Scallops {Pec- 
ten), of peculiar form ; " Cockscomb " oysters, and species of Liina 
and Pleurotomaria. One peculiarity of the Chalk Fossils is, the con- 
stant absence of the interior pearly layers of the shells, which have 
been removed subsequent to their imbedding. In the Green-sand 
strata, TrigonicB abound, and peculiar bivalves, of an extinct family {Hip- 
puritida), related to the recent Chama. Case 1, Room VI. 
6. Jurassic, or Oolitic Shells. (Cases 2 and 3, Room V.) The 
shells of the Portland stone, Bath stone, and other Oolitic rocks, and of 
the Lias, include numerous species of Trigonicp,, the internal casts of 
which are often found, whilst the shells have been dissolved and removed 
from the rock; they are called " horse-heads" by the quarry-men, and 
are sometimes silicified, and contain traces of the shell-fish itself. 
Amongst the Oolitic oysters, are some whose shells have been moulded 
on Trigoni(B and Ammonites. 
7. The Shells of the Triasstc System in Case 4, Room V., con- 
sist of the original specimens figured and described by Dr. Klipstein, in 
his work on the fossils of the salt-marls and Alpine limestone of 
Austria. 
PALAEOZOIC shells. 
8. Magnesian Limestone (Permian), of Northumberland and 
Durham. (Case 4.) 
9. Carboniferous Limestone, and Coal-measures of Britain and 
Belgium. (Cases 4 and 5.) Chiefly from the collection of Professor 
De Koninck, of Liege. 
10. Devonian System. (Case 5.) Devonshire and the Eifel. 
11. Silurian System. (Cases 5 and 6.) Presented by Sir Roderick 
Murchison, Bart., K.C.B. 
chambered shells [Cephalopoda). 
The Shells of the chambered univalves [C€phaloj)oda),Ye\-Siiedi to the 
recent Nautilus and Cuttle-fish [Sepia], are placed in the Table Cases 
(7 to 12 and 14) of Room V. 
In Case 10 are placed the curious fossils named Aptychi and Tii- 
gonellites, now known to be the operculum or covering to the mouth of 
the shell of the Ammonite. 
In Case 1 1 the fossil Nautili are displayed. Those from the London 
Clay of Ilighgate and Sheppey are specially worthy of notice. 
