THE WORM SHELLS AND POD - SHELLS - FAMILY VERMETIDAE Shell tubular, with septa; regularly spiral when young; whorls free, irregular when adult; aperture round; operculum circular, concave on outside; body worm-like; head long, with tentacles and eyes; foot rudimentary. Mollusks usually attached to coral rocks or imbedded in sponges.
Genus VERMETUS, Ads.
Shell irregularly spiral, attached on one side or free; tube partitioned repeatedly; operculum small.
The Worm Shell (V. spiratus, Phil.) is a mollusk, notwith standing its very worm-like shell, which is yellowish brown, or white,like the calcareous coverings of certain marine worms. The spiral is close and regular at first, then it becomes free and wanders off in irregular, wayward fashion. Longitudinal, angled keels on the shell, distinguish this species. It may attain a length of 6 to 10 inches. To fit the attenuated shell, the body is much elongated. The foot is short and broad. There is a horny circular operculum fitting the aperture. The toothed tongue is truly molluscan.
These shells often form, as if for mutual protection, an intri cate, tangled mass. They are found in shallow water all along the Atlantic seaboard, in the West Indies and the Gulf of Mexico.
Genus SILIQUARIA, Brug.
Shell spiral, becoming free and irregular, with a longitudinal groove, or series of holes, its whole length; operculum elevated 167 The Worm Shells and Pod Shells and spiral outside. Mollusks live on coral rock or sponges on tropical shores.
The Pod Shell (S. anguina, Linn.) is like the spirally twisted pods of certain leguminous plants. The long open groove in the shell distinguishes it from the worm shell. This species begins as a close spiral, but soon becomes irregular. It is a heavy yellowish shell, cylindrical, 3 to 6 inches long, and one-half inch in diameter at its mouth. It is found imbedded in sponges.
Habitat.— Mediterranean Sea.
S. modesta, Dall, unmistakably a pod shell, occurs in deep water from Cedar Keys, west coast of Florida, through the West Indies.
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