CYPRÆA.
TRIVIA.
"You can be at no loss on seeing the shells of Cypræa, a large and beautiful genus, which remained unchanged for a long time. Lately, we find a few of the small species are become a new genus, Trivia.
"The character of the Cypræa is a longitudinal aperture, toothed, in the adult state, on each side. The spire is scarcely to be seen.
"While the shells are young they have the appearance of a Voluta or a cone; the aperture spreads more, and is without teeth.
"The individuals of each species pass through three different states:
"In the first, the form is very imperfect; it is like a thin cone, and shows no character of the genus; hence young students are perplexed if they chance to have a young cowry in their collection.
"In the second state, the shell is still thin, with a projecting spire; but attains its proper form.
"In the third, or adult state, the shell is thick, the colours are perfected, and the spire is very nearly concealed.
"When the animal becomes too large for its habitation, it has the power of leaving it, and forming a new one.[D]