SHELL GALLERY. 
41 
world's history, are exhibited on tables in the corners of the 
gallery, by case 7.* Some of the stalked forms (fig. 18) are 
merely the larval stages of the Feather-stars. 
The wall-cases contain types of the very various and diverse 
groups brigaged together as Worms or Yermes. 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 Echinoderms 
preserved in spirit, especially Holothurians, such as Trepangs. 
Fig. 12. — Giant Tortoise of Aldabra Island, Galapagos. 
V. A large gallery is devoted to the extensive division of ^iiell Gallery. 
MoLLUSCA, the exhibition of which is however mainly re- 
I 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 collection is contained in four parallel rows of table- 
cases, the arrangement commencing on the right as the gallery 
is entered. The first two rows contain the marine forms of 
Gastropods — a division which includes Snails, Slugs, Whelks 
(fig. 14), and all those Molluscs which crawl upon the under 
surface of their bodies ; the Cones, Volutes, Mitras, and Murices 
* ' Guide to the Shell and Star-fish Galleries (Mollusca, Echinodennata, 
f Vermes).' Price fonrpence. 
