THE DOVE SHELLS FAMILY COLUMBELLIDAE. Shell solid, small, ovately oblong or triangular, sometimes fusiform; spire exserted; anterior canal short; columella arched, tubercled below; outer lip thickened, uncurved at middle, toothed on inner face; epidermis present; operculum horny; head long, eyes at base of tentacles, foot prolonged in front; mantle not enfolding shell. Radula present, degraded, behind the head. A family of few genera and many species. Little is known con cerning the living mollusks. Their distribution extends into both warm and cold seas.
Genus COLUMBELLA, Lam.
Characters of the family. These handsome little mollusks crawl upon sand flats and on gravelly and rocky shores in the tropics and southward and northward to cold waters, in many parts of both hemispheres. There are upwards of eight hundred species named, but singularly, these have been erected upon shell characters chiefly; few of the living mollusks have even been seen, still fewer studied and figured. Lacking adequate knowledge, conchologists are throwing into the genus Columbella shells having the outer lip thickened and toothed on the inner edge. Study of the soft parts of various species will doubtless make radical changes in classification.
The Common Columbella (C.inercatoria,Linn.)lives in sand two to four feet below water level, The shell is solid, broad shouldered, with strong revolving ridges crossed by faint longi tudinal ones. The usual form is marked with streaks of brown and white across the whorls. Pink specimens occur, of plain colour or marked with fawn in irregular spots. In some forms yellow, in others chocolate prevail. The aperture is white or yellowish. Length, 1 to I inch.
H abitat. —Florida and the West Indies.
I 00 The Dove Shells The Rusty Columbella (C. rustica, Linn.), variable in form and colouring, is an ancient species, which in its broad forms resembles C. mercatoria. It is distinguishable by its smooth sur face and by the purplish depressions between teeth within the lip. The markings are usually bright zigzag blotches or streaks of brown on a white or orange ground. Length, 1 to I inch.
Habitat.—Mediterranean, West Indies and West Africa.
The Columbella (C. lunata, Say) has cres cents of chestnut crossing the paler ground colour of its whorls. The shell is fusiform, nearly smooth, with small aperture and lip faintly toothed. This minute mollusk is found abundantly. The animal is pale, the foot as long as the shell, the eyes black. In spring they are seen crawling on the sand in the shallows; their natural station is clinging to stones and seaweeds a few feet below the surface. Length, ÷ inch.
Habitat.—Cape Cod to Florida.
A number of species of small dove shells belong to the fauna of our west coast.
The Keeled Columbella (C. carinata, Hds.) is sometimes keeled, as its name implies, but sometimes not. The large northern shells, var. gausapata, are smooth, their tawny surfaces banded with brown and flecked with white. The outer lip is toothed within, and fairly thick. The typical C. carinata is not so long, with an abruptly angled shoulder on the body whorl. Var. Californiana is smaller and smooth, marked and coloured like var. gausapata. Length, 1 to 4 inch.
Habitat.— Sitka to Lower California.
The Golden Columbella (C. aurantiaca, Dal]) is orange yellow, translucent, gracefully fusiform, with five rounded whorls. The teeth on the lip are scarcely visible. Sometimes the whorls are marked with zigzags of chestnut. Length, -1- inch.
Habitat.— Monterey, Cal.
C. tuberosa, Carp., a little larger, with angled body whorls, varies from white to chocolate brown, from plain colour to spots, bands and zigzags of contrasting hues, as in var. variegata.
Habitat.— Santa Barbara and San Diego, Cal.
The Rosy Columbella (C. rosacea, Gld.) is striated, acutely cone-shaped, rosy white, but lacking teeth on the thin lip. This minute shell. 1 inch long, occurs from New England to Spitzbergen and Norway. It is obtained from the stomachs of fish.
rot The Dove Shells C. avara, Say, follows the Atlantic coast from Massachu setts to the west coast of Florida. It has a variable outline, and is nearly an inch long. The whorls are cancellated by inter secting stria, the lower half of the body whorl, however, has only the revolving ridges. The yellowish ground is blotched with brown. The small aperture has teeth on both lips.
This mollusk lives below low-tide level, and is most abundant on southern coasts. In life the shell has a dirty, brown epidermis.
Genus AMPHISSA, H. and A. Ads.
Shell whelk-like, longitudinally grooved, apex elongated; aperture spreading to form a wide anterior sinus; inner lip callous with folds below; outer lip with fine plaits inside.
The Wrinkled Amphissa (A. corrugata, Rye.), yellowish brown, slenderly tapering, with fine ridges, occurs from California northward. Length, i inch.
Habitat.— California.
The Wavy Amphissa (A .undata, Cpr.) resembles the preced ing species in size and form, but there are remote wavy ridges crossing the fine spiral lines from apex to base.
Habitat.— In mud off Santa Catalina Island, Cal.
102