Molluscs of all kinds afford many beautiful objects, and the observer should be very careful to examine the wonderful tongue-ribbon of the snail, the slug, the periwinkle, the whelk, and other similar molluscs. If meant to be examined by polarized light, the tongue-ribbon should be mounted in Canada balsam.
Crystals should always form part of a collection. Take those of common salt, nitre, sugar, chlorate of potash, salicine, &c.; indeed, anything that will crystallize should be prepared and mounted, as such objects will often be most useful when examining unknown substances.
| BIRD’S-HEAD PROCESS. | NOCTILUCA. | PEDICILLARIÆ. |
BIRD’S-HEAD PROCESS.
NOCTILUCA.
PEDICILLARIÆ.