Page:Natural History, Mollusca.djvu/193

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181
WHELKS, ETC.


teeth placed three in a row, of which the middle one is three-pointed, and the outer ones hooked. The mantle is produced into a short siphon; the foot is ovate, notched in front and obtuse behind.

Nearly a hundred species of the genus are found in the warmer seas, some of them of large size, and almost all with a very wide-spread aperture and short spire. Our own common Dog-Winkle (Purpura lapillus) approaches more nearly the form of Buccinum: it is an exceedingly variable shell in size, colour, and sculpture; its most common appearance is white or pale yellow, sometimes banded with light or dark brown, and sometimes wholly of a deep chocolate hue. The figure on page 38 will enable my readers to recognise it, especially as it is one of the most abundant of our native shells, occurring by thousands on every rocky shore.

I have already described in the introductory chapter of this volume, the purple secretion possessed by this mollusk, and the mode of applying it; the dye is common to the genus, and in a greater or less degree to many genera of the same family.

The Dog-Winkle is to be found attached to rocks and stones between tide-marks, and few who behold it sluggishly clinging to its hold, would suppose that it is as ravenous and ferocious a tyrant among its fellow mollusks, as the lion or leopard among the flocks. Yet abundant evidence exists to show that it habitually preys upon other shell-fish, both univalves and bivalves. Mr. Hanley has "seen a Purpura devour a Periwinkle in the course of an afternoon, when placed in the same vessel of sea-water, sucking its prey as it were out