42 
WEST WING. 
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. Case 4 is devoted to specimens of Echinodermata 
preserved in spirit, especially Holothurians, or sea-slugs and 
sea-cucumbers. 
Gallery. large gallery is devoted to the extensive division of 
MoLLUSCA, the exhibition of which is however mainly re- 
stricted 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 i^autilus, 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 Eazor-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 
of the shell is closed in some forms ; also specimens illustrating 
the formation of pearls, and other special points of interest 
connected with the group. 
A special guide-book to the Shell and Star-fish galleries is 
