ON COLLECTING AND PRESERVING SHELLS. 121 
roots of trees, hollows and crevices of rocks and walls ; some lie under 
stones or pieces of wood, or in the earth ; others climb shrubs, and 
in tropical climates even lofty trees. Their haunts vary according 
to the weather and the season. They come out early in the morning, 
and after rain. Some bury themselves in moist places during the 
dry season, or burrow under leaves, grass, or stones, often closing the 
mouths of their shells with a white secretion to prevent evaporation 
during the period of torpidity. 
The smallest shells, especially of laird species, and young imperfect 
shells should be collected. 
In all cases “live shells,” i.e. shells in which the animal is alive, 
are to be chosen ; but when these cannot be procured, “ dead shells,” 
which have not lost their lustre or their colour, especially those of 
rare species, should be preserved. 
With regard to the mode of preserving shells : — 
1. No attempt should be made to clean them, or to remove the 
furry skin, more or less thick, with which they are often covered, 
beyond removing with a soft brush any mud or sand adhering to 
them. 
2. The animals of land and fresh-water shells may be killed by 
immersing them for a few minutes in boiling water, after which the 
bodies may be easily extracted whole with any suitable instrument— 
e.g. a fork or a pin, according to size. Hot water should not be 
used with marine shells: it often destroys their lustre. They 
should be buried, if time permits, in sand, or other dry material, 
until the animal dries up (in small shells) or rots (in large 
specimens); or they may be drowned in cold fresh-water, and hung 
up in the air to dry or rot away. In the former case, if an oper¬ 
culum (with which many species, both marine and land, close their 
mouths, more or less partially) exists, it will, generally in the case of 
land shells, remain in its place, adhering to the shell. In the latter 
the decayed matter should be washed out, and the operculum, if any, 
replaced and fixed, say, on cotton filling the shell. This applies 
equally to land shells. 
3. Care should be taken not to injure the edge or lip of the mouth 
of Univalves, or the ligament of the hinge of Bivalves. When 
Bivalves gape on dying in water, or it the ligament be broken,, the 
