SHKLL GALLERY. 
53 
by models of Trichina, and the anatomical structnre of various 
other forms is shown by the aid of diagrams. Case 3 contains 
the free-living Terrestrial and Marine Worms, the Leeches, and 
Gepliyreans. Case 4 is devoted to specimens of Echinoderms 
preserved in spirit, especially Holothurians, such as Trepangs 
or Sea-Cucumbers, the Beche dc Mer of the French. 
V\ii. 28. — Common Whelk {Buccinum un latmn), a tyi)ical Gastro])0(l. 
a, siphon ; &, foot ; c, tentacles ; f?, eyes ; fi, operculum. 
Fig. 29. — Left Valve of Giant Clam (Tridania gigantea), a typical Bivalve. 
(Leugth, 36 inches ; weight, 154 lbs. ; weight of the two valves, 310 lbs.) 
V. A large gallery is devoted to the extensive division of Shell Gallery. 
, MoLLUSCA, the exhibition of which is, however, mainly re- 
I striated to their shells. In some cases the form of the " animal 
itself is shown either by specimens in spirit or by means of 
models. 
Tlie collection is contained in four ])aranel rows of table- 
cases, the arrangement commencing on tlic riglit as the gallery 
