The Auger Shells - Family Terebrim

THE AUGER SHELLS - FAMILY TEREBRIM. Genus TEREBRA, Brug.

Shell heavy, long, taper-pointed, regularly spiral, of many flat whorls; aperture small, notched in front; columella without folds; operculum horny, annular; head large with eyes on tips of tentacles; foot round in front, elongated behind; radula present; proboscis large. A single genus of about 170 living and 25 fossil species. Inhabit shallow water in warm seas.

Few of the members of this tropical family are found in the cold waters of our coasts. These species are small and dull com pared with the large and highly coloured species represented in museum collections. All have the characteristic tapering spire with many flat whorls. They are usually polished and mottled or banded with some shade of brown on a pale ground. Some are trimmed with nodules upon the whorls.

The Variegated Auger Shell (T. varie gala, Gray) is streaked and spotted with brown on a whitish ground colour. A strong raised band revolves below each suture. The remaining part of the whorl is flat and finely striated. Fine wavy folds cross these striations. The raised bands bear prominent cross folds, between which are bright spots of brown. The body whorl has a central band of white dividing the cloudy brown cross streaks. The shell is polished, china-like and heavy. Length, 21 to 31 inches.

Habitat.— West Africa, China Sea, Galapagos Islands to Lower California.

The Spotted Auger Shell (T. maculata, Linn.) is a good type of the tropical members of the family. Heavy, solid, with many closely wound, flattened whorls winding down from a taper-pointed apex, it forms a needle cone of extreme elegance and mathematical exactness. The lower whorls are smooth, the upper ones longitudinally ridged. The ground colour is creamy white.

105 The Auger Shells On it are wound two bands of coloured spots, the upper one of chestnut, the lower of purple or slate, with a dark line separating the two. The Polynesians fashion these shells into chisels for use in building their canoes. The flesh they eat. Length, 4 to 6 inches.

Habitat.— South Sea Islands.

T.

dislocata, Say, is a grayish brown or yellowish white auger shell, I to 2 inches long, with surface sculptured by wavy longitudinal folds and fine spiral groves. The whorl bears a raised, beaded band just below the suture. The columella has one distinct ridge.

Habitat.— North Carolina to West Indies.

T.

protexta, Conrad, is very slender, with somewhat convex, finely striated whorls crossed by fine, sharp-edged longitudinal folds, set close together. It is china-like in texture, brown shad ing lighter. Length, 1 inch.

Habitat.— Gulf Coast of Florida to Cape Hatteras.

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