GROUND FLOOR. 
35 
im. tlie Caribbean Seas. These deep-sea forms, so abundant in 
earlier periods of the world's history, are exhibited on tables 
in the corners of the gallery, by case 7. 
The wall-cases contain types of the very various and different 
groups which are put together as Worms or Vermes. Case 1 con- 
tains the Tape-worms or Cestoda, and the Flukes or Trematoda, 
the life history of a type of each being illustrated by specimens, 
figures, and models ; in case 2 the Eound- worms are illustrated 
by models of Trichina, and the anatomical structure of various 
other forms is shown by the aid of diagrams. Case 3 contains 
the free-living Terrestrial and Marine Worms, the Leeches, and 
Gephyreans. 
V. A large gallery devoted to the extensive division of Shell Gallery. 
MOLLUSCA, the exhibition of which is however mainly restricted 
to their shells. In some cases the form of the animal itself 
is shown either by specimens in spirit or by means of 
models. 
The first table-case on the left as the gallery is entered contains 
the Argonauts, the beautiful pearly Nautilus, the rest of the 
Cephalopods (Octopus, Squids, &c.), the fragile glassy Pteropods, 
and the Cones, one of the most beautiful groups of the Gastro- 
pods, a division which includes Snails, Whelks, Slugs and all 
those Molluscs which crawl upon the under surface of their body. 
They are contained in cases 1-17. The Bivalves or those 
Mollusca which, like the Cockle and Oyster, are protected by a 
shell formed by two pieces or valves, are arranged in cases 
17-26. The most generally known of this division are 
the Venus-shells (case 17) ; the Cockles (case 19) ; the Giant 
'Clam, sometimes weighing as much as 500 lbs. each (case 
20); the Piddocks and Teredos, borers in wood and stone 
(case 19); the Kazor-shells (case 20); the Pinnas (case 24); 
Scallops and Thorny Oysters (case 25) ; and the True Oysters 
.(case 25). 
A fine series of very large shells and some interesting 
Cephalopods in spirit occupy four upright cases at the ends of the 
room; and near the entrance to the gallery are placed some 
small table-cases, containing series of the eggs of Mollusca and 
of their opercula or lids by means of which the opening or mouth 
vof the sliell is closed in some forms ; also specimens illustrating 
D 2 
