THE TUN SHELLS - WINE JARS FIG SHELLS - FAMILY DOLIIDAE.
Genus DOLIUM, Lam.
Shell almost globular, with wide mouth; lip ruffled; columella channeled; basal canal straight. Used for lamps, vases, etc. Fifteen species.
The Helmet Tun Shell (D. galea, Linn.), one of two species found on our coast, is a good type of the family. The shell is eight to nine inches long and fully as broad. Unlike the conchs and helmets, the tun shells are thin and light in weight, though large. The spire is small and sunken, with a deep suture in the large body whorl which constitutes the greater part of the shell. The surface has a series of parallel, deep cut, revolving grooves crossed by many faint lines of growth. The even fawn colour of the exterior is brightened by dashes of darker brown on lip, columella and spire. The umbilicus is narrow and deep.
Habitat.— North Carolina to Brazil.
The Partridge Tun (D. perdix, Linn.) is marked with crescents of white on a brown ground colour, strikingly resembling the plumage of a partridge. The spire of this species is much elevated. The unusual range is noteworthy. Length, 5 to 9 inches.
The Tun Shells. Wine Jars. Fig Shells Habitat.— Indian Ocean, Polynesia, West Africa, West Indies, Florida Keys, Brazil.
The Apple Tun(D.pomum, Linn.) is a solid little shell, yellow ish brown, clouded and mottled with white in about equal pro portions. The spire is depressed, with a deep suture; the whorls bear broad, low, rounded ridges. The columella is ridged and umbilicated, with a slight excavation in the middle. An external groove sets off the flaring lip, which is thickened and crossed by sharp ridges just back of the incurving edge. These shells are
rather heavy for their size. Length, 3 inches.
Habitat.— Red Sea, Indian Ocean, Philippine Islands.
Sub-Genus MALEA The Grinning Tun (D. ringens, Swn.) is the heaviest species in the genus. The grin is produced by the turning backward of the outer edge of the lip. The columella has a distinct excava tion in the middle with prominent ridges above and below it. The exterior of the shell has deep wide grooves and rounded ridges which give the flaring lip a scalloped edge. Length, 4 to 9 inches.
Habitat.— Peru and Panama.
Genus PYRULA, Lam.
Shell very thin, pear-shaped, finely ribbed, cancellated, ending in an open canal at base; spire depressed, short; lip thin, smooth; operculum and umbilicus wanting. Foot large, with wide spread; siphon, head and tentacles much elongated and narrow; mantle lobes reflected over sides of shell in use. A few species only.
The Paper Fig Shell (P. papyratia, Say) is found from Beaufort, N. C., down the coast to the West Indies. I have picked up many fine specimens on the Gulf coast of Florida; how the delicate, almost transparent, things escape shattering in the surf is more than I can explain. I never saw the living mollusk. The general colour of the shell is brownish white with faint brown lines drawn down from the spire. Inside, the brown is darker. There are no spots on the finely cancellated surface. Length, 3 to 4 inches.
Arthur Adams describes an East Indian species as a very 141 The Tun Shells. Wine Jars. Fig Shells shy and sensitive mollusk, hurrying along on its broad foot and carrying its light shell with ease and grace. In captivity it climbed the sides of its glass prison with equal ease and celerity. Wonder ful blending of dainty colours he saw in the extended foot, mantle and head: pink and violet elegantly marbled and dotted with red and yellow. In front the long neck bore the head aloft, and the large black eyes peered about in a remarkable manner.
The Turnip Shells, genus Rapa, are illustrated by R. papyrifera, which exaggerates the characters of the graceful paper fig shell.
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