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Family Volutidae

SHELL usually thick, often shining, showy, usually large, fusiform, cylindrical, oval or globular; columella projecting anteriorly, with several revolving folds; aperture notched, canal not produced; apex blunt, papillary; operculum generally wanting; body highly coloured; foot broad in front; head dilated into flat lobes on which are borne the two sessile eyes at the bases of the tentacles; siphon large, lobed at base; radula with strongly cusped teeth.

A carnivorous family living at considerable depth in tropical and sub-tropical waters, chiefly in the southern hemisphere.

Genus VOLUTA, Linn.

Shell ovate or fusiform, thick, solid, spire usually short, shoulders of whorls usually angled, sometimes bearing nodes or spines, aperture rather narrow; columella with a thick callous deposit, and winding plaits; lip thickened back of the sharp edge; sometimes almost reflected. A remarkable genus whose distribution centres in Australian waters.

The volutes might be called the "spiral shells" were this trait not constant among the gasteropods of sea and land. They are named for the folds upon the columella, a character they do not monopolise by any means. The spire is always prominent and always has a rounded, mammillate apex. The operculum is absent except in V. musica. In spite of its lack of distinctive characters in the shell, this family is not hard to distinguish from the few other "first families" of the mollusks. They are handsome, aristocratic-looking shells, of graceful form, good size and elaborate ornamentation. Amateurs are often enthusiastic collectors of volutes, and many rare and valuable species are to be found in private cabinets. Our native species is one of the most rare and valuable sea shell to be found in American waters. Several tropical species have long been known only by single specimens in European cabinets.

M. Duhant-Cilly, in 1840, described the eggs of volutes and their development. The mollusks were seen in the clear water of Magellan's Straits, each clasping the shells of a dead bivalve. In the convexity of one valve the volute had deposited a membranous mass, resembling in shape and transparency a watch glass. Some looked milky; others showed three or four perfectly formed volutes swimming about in the now clear fluid. In February, the late summer of that region, the young have attained considerable size. The transparent capsule has become leathery and is three to four inches across, more than half the size of the mollusk that laid the eggs. D'Orbigny conjectures that it expands after coming in contact with the water.

The Music Volute (V. musica, Linn.) has its whorls adorned with sets of parallel revolving lines, which look like bars of music, set the ordinary distance apart. The typical form has its "notes" grouped in single lines directly above and below the bars. Fine dots are thickly scattered between the two rows of large spots. The ground colour is a creamy flesh tint. The lines are bright chestnut, the dots dark brown. A deep bluish chocolate underlies the other colours on the body whorl. Faint wavy lines set close cross the bars. Nodules on the shoulder of all the whorls become very prominent on the last one. The lip turns out; the thick margin is marked with short stripes of dark brown. The columella has five main folds on a thick callus.

This species exhibits great variation of colouring, but the pattern is practically constant. Shells vary in length from two to four inches. One is pinkish red and small, var. carneolata; another is elongated in form, with pale colouring, var. thiarella. Var. laevigata lacks tubercles; var. sulcata has ribs from its tubercles, and is pale fawn-coloured.

This West Indian volute is the only species having an operculum. This is shaped like a long oyster shell, with the nucleus at the apex. The eggs are laid in flattened oval capsules the size of a finger-nail, in the concave of deep bivalve shells, to which they are glued singly, three or four in each shell.

The Flag Volute (V. vexillum, Lam.) is a small flesh-tinted shell with narrow bands of orange revolving around its whorls. Faint cloudings of the same colour often occur, and blotches of it mark the nodules on the shoulder of the body whorl. The apex is very sharp.

This very distinct and rare species is three to four inches long, and comes from the Indian Ocean.

The Waved Volute (V. undulata, Lam.) is also marked with wavy lines of rich chestnut--a flag with its stripes running longitudinally instead of spirally. It is three to four inches long, fusiform and slender, as elegant in shape as in colour and pattern.

Habitat.--Australia.

The Imperial Volute (V. imperialis, Lam.) wears a crown of upturned hollow tubercles on the outer three whorls of the peaked spire. Over the shining salmon-coloured surface is a netted pattern made of zigzag chestnut lines, merging occasionally into triangular blotches of solid brown. The pattern is the same on the spire, but the colour is darker.