Search the Dictionary

Many-valved; having more than two valves; -- said of certain shells, as the chitons.

A genus of marine gastropods, having rough, and frequently spinose, shells, which are often highly colored inside; the rock shells. They abound in tropical seas.

A kind of shell limestone, whose strata form the middle one of the three divisions of the Triassic formation in Germany. See Chart, under Geology.

-- Music pen, a pen for ruling at one time the five lines of the musical staff. -- Music shell (Zoöl.), a handsomely colored marine gastropod shell (Voluta musica) found in the East Indies; -- so called because the color markings often resemble printed music. Sometimes applied to other shells similarly marked. -- To…

Any one of many species of marine bivalve shells of the genus Mytilus, and related genera, of the family Mytidæ. The common mussel (Mytilus edulis; see Illust. under Byssus), and the larger, or horse, mussel (Modiola modiolus), inhabiting the shores both of Europe and America, are edible. The former is extensively used…

A genus of bivalve mollusks, including the common long, or soft-shelled, clam.

A genus of marine bivalve shells, including the common mussel. See Illust. under Byssus.

A pearly substance which lines the interior of many shells, and is most perfect in the mother-of-pearl. [Written also nacker and naker.] See Pearl, and Mother-of-pearl.

The umbones of a bivalve shell.

er allied genera (family Naticidæ.) They burrow beneath the sand, or mud, and drill other shells.

Like or pertaining to the nautilus; shaped like a nautilus shell. -- n.

es are found living in the tropical Pacific, but many other species are found fossil. The shell is spiral, symmetrical, and chambered, or divided into several cavities by simple curved partitions, which are traversed and connected together by a continuous and nearly central tube or siphuncle. See Tetrabranchiata.…

muth, lead, and copper occuring in acicular crystals; -- called also aikinite. -- Needle shell (Zoöl.), a sea urchin. -- Needle spar (Min.), aragonite. -- Needle telegraph, a telegraph in which the signals are given by the deflections of a magnetic needle to the right or to the left of a certain position. -- Sea ne…

A division of vermiform gastropod mollusks, without a shell, belonging to the Isopleura.

A genus including numerous species of shells resembling Nerita in form. They mostly inhabit brackish water, and are often delicately tinted.

A rounded seed, rather smaller than a nutmeg, having a hard smooth shell, and a yellowish or bluish color. The seeds grow in the prickly pods of tropical, woody climbers of the genus Cæsalpinia. C. Bonduc has yellowish seeds; C.Bonducella, bluish gray. [Spelt also neckar nut, nickar nut.]

of Biblical history, in the time of the Deluge. Noah's ark. (a) (Zoöl.) A marine bivalve shell (Arca Noæ), which somewhat resembles an ark, or ship, in form. (b) A child's toy, consisting of an ark-shaped box containing many different wooden animals.

Resembling in form or structure a foraminiferous shell of the genus Nodosaria. -- n. (Zoöl.)

The tip, or earliest part, of a univalve or bivalve shell.

A genus of small marine bivalve shells, having a pearly interior.