The Chink Shells
THE CHINK SHELLS Genus LACUNA, Turton Shell thin, ovate, turbinate or round, covered with epidermis; aperture half-moon shaped; columella with groove or chink leading to umbilicus; lip sharp; operculum thin, spiral.
The Atlantic Chink Shell (L. vincta, Turton) looks at first glance like an elongated and thin specimen of Littorina. The spire is smooth, horn-coloured, or banded with brown on a purp lish ground. The distinctive generic feature is the deep columellar groove. It lives upon seaweeds in sheltered coves, and is often quite as well represented as the periwinkles in the debris of an inshore wind. Length, , inch.
Habitat.— Arctic seas to New Jersey.
The Chink Shell (L. porrecta, Cpr.) has a wide groove, and the body whorl is much enlarged. The creature is found on seaweed. It is about inch in diameter.
Habitat.— Vancouver Island to San Diego, Cal.
177 The Periwinkles and Chink Shells L. variegata, Cpr., streaked with chestnut, often beaded with white on the peripheral margin, has about the same distri bution, but is one-half as large as L. porrecta.
L.
pallidula, Da C., with widely flaring mouth and wide umbilicus, is a yellowish species found in the North Atlantic. It is about / inch in diameter.
Habitat.— New England.
L. divaricata,
Fab., is a glossy little chink shell, with elon gated spire, whitish, often variously banded with brown and white. Length, about / inch.
Habitat.— All cold waters of northern hemisphere, including New England and northwestern coast.
Genus MODULUS, Gray Shell top-shaped, solid; whorls grooved and tubercled; umbilicus narrow; columella grooved, ending below in a sharp tooth. Few species.
The Florida Modulus (M. Floridanus, Conn) has a depressed spire, strongly ribbed, and crossed above the periphery by short, oblique nodular ridges. The umbilicus and the sharp tooth of the columella are the best distinguishing features. Its colour is dirty white, often tinged with brown or olive green. Diameter, / to I of an inch.
Habitat.— West coast of Florida Keys.
Genus FOSSARUS, Phil.
Shell small, spiral, compact, ridged, with umbilical groove on the columella. Littorine mollusks on seaweeds.
The Elegant Fossarus (F. elegans, Verr.) has its few coils most beautifully sculptured with strong winding ridges crossed by deeply chiseled, close striations. The large, round mouth crowds the grooved columella and almost covers the pit. The outer lip is frilled. Length, / inch.
Habitat.— Rhode Island to Cape Fear.