40 
NORTH GALLERY. 
[upper 
contains the Cirripedia, represented at the present day by the Ship 
Barnacle and the Acorn-shell. The second, contains the Bivalved 
Crustacea, Phyllopods and Ostracods ; and a portion of the Trilobites ; 
the remaining portion being in Table Case 7. In the adjoining Win- 
dow-recess Case is exhibited a series of Crustaceans belonging to 
the JSurypterid(B and LimuUda, or King-Crabs. The gigantic Euryp 
teridcB are extinct, but the King-Crab is found living at the present 
day. Fine exanaples of Limulus, from Solenhofen, and of Slimonia, 
from Lanarkshire, are placed on Case 9. 
Case 7 contains the Trilohita, the Isopoda, and the Decapoda (Crabs 
and Lobsters). Of the Trilobites, by far the greater part are from the 
Wenlock Shale and Limestone of Worcestershire and Staffordshire, and 
the Silurian rocks of Bohemia. The " Dudley LiOc\ists'\Ca/yme?ie Blu- 
menbachii) and the great " Barr Trilobite " [Illcenus Barriensis) are 
among the earliest fossils known to science. Fossil Lobsters are 
found to extend from the Coal Measures to the present day; whilst 
true Crabs first appear in the Upper Oolite. Specimens from the 
Lias of Lyme, the Oolite of Solenhofen, and the London Clay of 
Sheppey, are most deserving of attention. 
The Fossil Shells (MoUusca) are divided into four groups. 1. Lamp- 
shells [Brachiopoda). 2. Ordinary Bivalves (Conchifera). 3. Spiral 
JJuixahes (Gasteropoda). 4. Chambered Univalves (Cep/mZo^Oiia). 
Lamp-shells [Brachiopoda). Cases 2 and 3, Boom VI. Those from 
the Tertiary strata belong to existing genera, and some to existing 
species; but others, like the great Terehratula oi the Suffolk crag, are 
unknown in a recent state. The Chalk species are no longer living, and 
belong chiefly to the genera Terebratula, Thecidium, Rhynchonella, and 
Terehratella, of which all, excepting the last, appear to be verging 
towards extinction, or are scantily represented by existing species. 
The Fossil Bivalves [Conchifera), and Spieal Univalves [Gas- 
teropoda), have been arranged in parallel groups, according to their 
geological age. 
TERTIARY FOSSIL SHELLS. (RoOm VI.) 
1. Newer Pliocene. The Shells of this Geological period are 
displayed in the Table Cases numbered 11 and 12, and in part of 
Case 13. 
2. Older Pliocene. In Table Case 10, will be found Shells 
of the " Crag " of the Eastern Counties, of which more than half 
are still existing, either in British Seas, in the Mediterranean, or on the 
coasts of Norway and North America. And in part of Table Case 
11 is exhibited a collection of Lithodomous Mollusca, with their 
crypts or cells: they are chiefly from the Crag of Suffolk. 
3. Miocene, or " Middle Tertiary." To this period are referred the 
Shells from Touraine, Bordeaux, and Poland, in Case 6 ; from Malaga, 
Case 4; and from St. Domingo, Case 13. Some of the Shells col- 
lected in the Canary Islands, and in Madeira, by Sir Charles Lyell, 
are referred to the same period : they are also in Table Case 13. 
