This Plate commences with other forms of the Limpet tribe, Fissurella, 1, 2, with a hole at the top; Puncturella, 3, with a fissure near the top; and Emarginula, 4-6, with a slit at the margin. Haliotis, 7, or pearly "Ear-shell," leads to the Trochidæ, or "Tops," 8-27.
Ianthina, 1-4, is genus of oceanic molluscs, which are provided with a beautiful floating apparatus, on which the female carries her egg-bags.
Neritina, 5, and the Paludinidæ, 8-11, live in fresh-water. The animal of Paludina is sprinkled all over with bright, golden specks. The Littorinæ, or "Winkles," 12-24, are marine, and frequent the shore among seaweeds. Lacuna, 25-32, belongs to the same family.
Are small genera, various in their characters and habits, but reasonably included in the last family, Littorinidæ.
The animals of Turritella, 1-3, and Cæcum, 6, 7, are not unlike, although the shells are so different; eyes at the base of the tentacles, a short foot, and horny operculum. The somewhat similar animal of Aporrhais, 4, 5, is brilliantly coloured with gold and red. Cerithium, 8-10, differs from Cerithiopsis, 11-15, more in regard to the animal than the shell; the latter animal has a retractile proboscis, and its operculum is not spiral.
Chemnitzia, 1-11, and Truncatella, 12, together with Stylifer, Eulima, and Odostomia, form the family of Pyramidellidæ. Notwithstanding the difference in the shells, the animals are very similar, having a retractile proboscis, and eyes immersed at the base of their tentacles.