7 to 10 mm. in length, very similar to punctostriatus, but larger, very much thicker-shelled, glossy, opaque milk-white with light orange-brown suffusions on the body whorl. Commonly dredged in a few fathoms of water.
Family RINGICULIDAE
Genus Ringicula Deshayes 1838
Ringicula semistriata Orbigny Orbigny's Helmet-bubble
North Carolina to southeast Florida and the West Indies.
2 to 3 mm. in length, thick-shelled, resembling a miniature Phalium or Scotch Bonnet. 4 globose whorls, spire elevated. Aperture oblong; columella thickened by 3 folds, 1 above, 2 below. Outer lip very thick, swollen in the middle by a large tooth. Whorls, white, smooth, except for fine striations on the base. Not uncommonly dredged from 34 to 107 fathoms.
R. nitida Verrill (Verrill's Helmet-bubble from Maine to the Gulf of Mexico. 100 to 500 fathoms) is exteriorly smooth, with a simple, thickened outer lip, and with 2 smaller, spiral ridges on the columella.
Family HYDATINIDAE
Genus Micromelo Pilsbry 1894
Micromelo undata Bruguière Miniature Melo
Lower Florida Keys and the West Indies.
½ inch in length, oval, rather thin and moderately fragile. Characterized by its whitish to cream color overlaid by 3 widely spaced, fine spiral lines of red and by many or few axial, wavy, lighter red flammules or lines. Uncommon. Found at low tide.
Genus Hydatina Schumacher 1817
Hydatina vesicaria Solander Brown-lined Paper-bubble
South half of Florida and the West Indies.
1 to 2½ inches in length, very thin, fragile, globose. Periostracum thin, buff to greenish. Shell characterized by many close, wavy, brown spiral lines. Animal large and colorful. Foot very broad. Moderately common in certain shallow, warm-water areas where they burrow in silty sand. Formerly called H. physis Linné which, however, is believed to be limited to the Indo-Pacific.