24 
GUIDE BOOK TO THE BRITISH MUSEUM. 
has a shelly valve that closes the mouth of the shell, placed behind the 
plait on the pillar, and the Achatince. Many of these shells deposit a 
large egg covered with a hard shell, like the eggs of birds. The eggs of 
different kinds are in the Case. 
Table 29, 30. The Fresh- water Shells, as the different genera allied 
to Auricula , amongst which is the Carychium , the most minute of the 
British land shells ; and the different kind of pond snails ( Limneus ), 
coil shells ( Planorbis ), and fresh-water limpets ( Ancylus ). The 
Amphiboloz , from Australia. The Siphonarice , which so much resemble 
the limpets ; and lastly, the various kinds of Cyclostomce and Helicince . 
Tables 31 — 45. The Bivalve Shells, 
Which are under arrangement into tribes. 
Table 46. The Lamp Shell ( Terebratula ); Duck muscles {Lin- 
gula) ; the Cranice and Discince , the upper valves of which have been 
mistaken by some authors for limpets; the Bones of Cuttle Fish 
(Sepia); the cartilaginous lances of sea leaves ( Loligo ), sometimes 
called sea pens. The fossil Belemnites , which are supposed to be similar 
to the small homy process at the end of the cuttle fish bone. The 
crozier shell ( Spirula ), and the different kinds of Ammonites and 
Nautili. 
THE NORTHERN ZOOLOGICAL GALLERY. 
FIRST ROOM. 
This room may be for the present considered as an appendage to the 
two foregoing. 
The Wall Cases. A series of the skulls of the larger Mamma- 
lia to illustrate the characters of the families and genera, and of the 
nests of birds, and the arbours of the two species of Bower Bird ; the 
one ornamented with fresh- water shells and bones, and the other with 
feathers and land shells, & c. 
The Table Cases. The tubes of Annulose Animals, the casts 
of the interior cavities of Shells, and various specimens of shells, illus- 
trative of the diseases and malformation of those animals. 
Tables 1, 2 contains the shelly tube formed by the Serpulce, which 
have often been confounded with shells. The tubes of sand agglu- 
tinated together by the juices of the animal formed by the Amphitrites. 
Tables 3, 4 contain specimens of shells, exhibiting the different 
size of different specimens in their adult age, the changes of form which 
occur in the shell during the growth of the animal, the changes 
which take place in the cavity of shells, the manner in which shells 
are mended by the animal after any injury, and also how the animal 
covers any excrescence which attaches itself to a shell, or removes any 
part which is in the way of its enlargement. 
Tables 5, 6 contain a series of plaster casts of the interior cavities 
