The Wedge Shells

THE WEDGE SHELLS Genus DONAX, Linn.

Shell wedge-shaped, triangular, ventricose, posterior end abruptly truncated just behind the hinge; anterior end prolonged and rounded; surface finely cancellated, the valve margins meet in fine interlocking teeth; hinge teeth, three in each valve, liga ment external. Mantle fringed; siphons short, divergent; foot large, elastic, pointed.

A very distinct genus of small bivalve mollusks inhabiting sandy shores of warm seas.

The Variable Wedge Shell (D. variabilis, Say) is the pret tiest and daintiest bivalve to be found in American waters. I have at hand in the original package the first dozen I ever saw, sent me from Florida packed in a skein of Sea Island cotton. They are like gay tropical butterflies, their flat, paired valves spreading like wings, exhibiting a range of colour that justifies the specific name. There are pinks and salmons, pale greens and yellows, lavender and fawn and white. Rays of colour from the beaks are crossed by narrow bands that centre there; the result is a plaid effect of unusual and attractive patterns. Their dimi nutive size make them seem more like jewels than shells.

The brightest of them fades when exposed to light. No cabinet specimen can compare with the living jewels that I found by thousands in the sand all along the Florida gulf coast. They sprinkled the yellow floor as each wave receded. But before I could pick up half a dozen they had gone. The pointed tongue thrust obliquely out and downward enters the wet sand, lifts the shell, and draws it under cover.

342 The Tellen Shells. Sunset Shells. Wedge Shells Floridians call them "pompano shells," and know them best as the basis of a most delicious soup. A sieve of suitable mesh is used to separate the shells from the sand in which they hide. It is not unusual to see women and children gathering the shells for use in the making of shell flowers and other articles which winter visitors buy. The valves are even punctured and strung, an inch or more apart, on coloured silk threads to be hung in doorways as por tieres. I saw one of these that was really exquisite; the colours blended as in a rich mosaic of small and uniform pattern; the dom inant colour, a warm heliotrope, was furnished by the strong silk threads. A loose crocheted stitch hung each shell securely in its place. Not the least attractive feature of this unique, shin ing fabric was the very musical rattle it had whenever anyone brushed it in passing. Thirty dollars was paid for this piece of work which contained as many thousand shells. The largest

was half an inch long.

The Smooth Wedge Shell (D. lovigata, Desh.) so strongly resembles its Floridian relative as to make a separate name seem unnecessary. White and shades of blue prevail as schemes of ornament, though lemon yellow and other colours are seen. Boys with push carts gather these miniature bivalves by the bushel at low tide, and sell them fresh to the townspeople at ten cents a quart. The broth is considered especially desirable for invalids.

Habitat.— Southern California.

The California Wedge Shell (D. Californica, Conr.) has the posterior end prolonged and rounded, so as to bring the two beaks near the middle of the shell. This is not the typical Donax form The valves are extremely light and thin, and ordinarily lack the vivid colour that decorates the shells of the other two forms Some have radiating stripes of blue or black.

Habitat.— California.

The Hide Wedge Shell (D. scortum, Linn.) is the largest species. Its valves are white and china-like, locking in front with strong teeth. The posterior end forms a heart-shaped concav ity set off from the sides by sharp, angular ridges. The lines of growth are edged with upturning frills, and these are fluted by fine radiating ridges. Young shells wear rows of spines on the borders of the posterior area, and wide frills on the anterior end of the shell. Length, 21 inches.

Habitat.— Ceylon, Cape of Good Hope.

343 The Tellen Shells. Sunset Shells. Wedge Shells The Wedge Shell (D. denticulatus, Linn.) is finely grooved from the beaks outward, and the ventral mar gins meet in a series of interlocking teeth. These are larger and thicker shells than the Floridian species. The posterior area is set off by two-angled ridges. The white surface is rayed with red, blue or orange. Length, i inch.

Habitat.— West Indies.

Genus HETERODONAX,

Mi5rch Heterodonax bimaculatus, d'Orb., is excluded from the proper wedge shells by its thin, oval form, and concentric ridges. It is like them in being many-coloured, in rays and stripes, purple, salmon and white. It is distinctly larger at San Diego than at San Pedro. The name calls attention to two distinct spots which are usually plainly seen. Length, less than I inch.

Habitat.— Southern California. Florida.

Genus PSAMMOBIA, Lam.

This genus is represented in California by

P. Californica, Conr., a beautiful white porcellanous shell rayed with red. It reaches five inches in length at Puget Sound.

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