THE APPLE SNAILS - FLASK SNAILS - FAMILY AMPULLARIIDAE.
An amphibious family of tropical distribution in both hemi spheres, corresponding to the Paludinidx in ponds and streams of temperate regions. The gills lie in a large, partially closed breathing cavity, which adapts the mollusks to life out of water. In dry seasons they bury themselves in mud; indeed, they survive removal from water for months, breathing air, but probably keeping the air chamber moist. The typical genus has a green, shiny epidermis.
The large eggs are laid in limy capsules, which adhere in round masses to the stems of water plants. When fresh they are beautifully coloured, crimson, pink or bluish green.
Genus AMPULLARIA, Lam.
Lip continuous, reflected, thickened inside, operculum horny, with shelly coat outside. A large genus of striking coloration and size.
The Giant Flask Shell (A. gigas, Spix), as large as a man's clenched fist, is a formidable snail. The great aperture almost conceals the rest of the shell with its continuous flaring rim, as one looks down into its blue-banded depths. The spire is deeply channeled and sunken well into the inflated body whorl. The horny olive surface bears many narrow bands of green. The pit is deep; the lip yellowish and spotted. Diameter, 4 to 6 inches.
Habitat.— Brazil.
197 The Apple Snails. Flask Snails The Noble Flask Shell (A. nobilis, Rve.), has a more ele
vated spire, which gives the shell a squat, pear-shaped outline. The horny olive surface is obscurely banded with brown. The great aperture reveals a pale, unbanded interior, painted on the recurved lip with bright, dark red. Diameter, 4 to 5 inches.
Habitat.— Brazil.
In several other species the protruding thick lip is strikingly banded and coloured.
The Paper Apple Snail (A. papyracea, Spix) is thin-shelled and black as ink. Diameter, 3 to 4 inches.
Habitat.— Rivers of Western Brazil.
The Island Apple Snail (A. insularum, d'Orb.) has its green ish globose body whorl finely striated, and often creased as if hammered. The gaping mouth glows orange red. This species inhabits lakes and brooks, among the stems of water plants. A specimen survived a year's sojourn in a cabinet, reviving promptly when put into water.
Habitat.— Isles of Parana in the La Plata River.
Genus POMUS, Humphrey Lip thin at margin; operculum horny. Inhabits South America, West Indies and Florida. "Idol Shell" is an Indian name in South America, where the shells are venerated.
The Flattened Apple Snail (P. depressa, Say) is swollen almost to globular form, the spire flattened, the olive-green sur face banded with narrow lines of darker green and brown, unequally spaced. The aperture is oval and very large, with a thin lip, scarcely flaring. The pit is nearly closed. Length and breadth, 1/ inches.
Habitat.— Tributaries of St. John's River, Eastern Florida.
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