Spiny Mollusk
“I do not deny that it resembles a little the murmur of waves heard at a distance; but you must not think that the shell keeps in its folds an echo of the noise of the waves. It is simply the effect of the air going and coming through the tortuous cavity.
“This other belongs to France. It is common on the shores of the Mediterranean and belongs to the genus cassis.”
“It goes hoo-hoo, like the helmet,” Emile remarked.
“All those that are rather large and have a spiral cavity do the same.
“Here is another which, like the preceding, is found in the Mediterranean. It is the spiny mollusk. The creature that inhabits it produces a violet glair, from which the ancients derived, for their costly stuffs, a magnificent color called purple.”
Paludinidæ
“How are shells made?” asked Claire.