The Collaborative International Dictionary
Soft-shell \Soft"-shell`\, Soft-shelled \Soft"-shelled`\, a. Having a soft or fragile shell.
Soft-shell clam (Zo["o]l.), the long clam. See Mya.
Soft-shelled crab. (Zo["o]l.) See the Note under Crab, 1.
Soft-shelled turtle. (Zo["o]l.) Same as Soft tortoise, under Soft.
Douglas Harper's Etymology Dictionary
Usage examples of "soft-shelled".
New Orleans, or eaten himself ill, as we nearly did ourselves, on a generous mixture of clam-chowder, terrapin, soft-shelled crabs, Jersey peaches, canvas-backed ducks, Catawba wine, winter cherries, brandy cocktails, strawberry-shortcake, ice-creams, corn-dodger, and a judicious brew commonly known as a Colorado corpse-reviver.
Lifeforce glimpsed by the Muir is not just that the Startree Biosphere survives, not just that the Brotherhood survives, not just that our Ouster brethren survive, not just that our hunted and harried sentient cousins of the Seneschai and the Akerataeli and the erg and the zeplin survive, not just that the species known as humankind survives, but that our prophecies begin to be realized this day and that all species of beloved life -- humanity no more than the soft-shelled turtle or Mare Infinitus Lantern Mouth, the jumping spider and the tesla tree, the Old Earth raccoon and the Maui-Covenant Thomas hawk -- that all species beloved of life join in rebirth of respect as distinct partners in the universe's growing cycle of life.