SHELL n.
The hard calcareous or chitinous external covering of mollusks, crustaceans, and some other invertebrates. In some mollusks, as the cuttlefishes, it is internal, or concealed by the mantle. Also, the hard covering of some vertebrates, as the armadillo, the tortoise, and the like.
SPIRACLE n.
One of the external openings communicating with the air tubes or tracheæ of insects, myriapods, and arachnids. They are variable in number, and are usually situated on the sides of the thorax and abdomen, a pair to a segment. These openings are usually elliptical, and capable of being closed. See Illust. under Coleopte…
SPONTANEITY n.
ntaneous, or acting from native feeling, proneness, or temperament, without constraint or external force. Romney Leigh, who lives by diagrams, And crosses not the spontaneities Of all his individual, personal life With formal universals. Mrs. Browning.
STAFF n.
e (Arch.), a square rod of wood standing flush with the wall on each of its sides, at the external angles of plastering, to prevent their being damaged. -- The staff of life, bread. "Bread is the staff of life." Swift. -- Staff tree (Bot.), any plant of the genus Celastrus, mostly climbing shrubs of the northern hemi…