Zoology. Any of various filaments, bristles, or appendages on an animal thought to resemble a beard in some way. The gills of an oyster.

A natural movable joint: spec. (a) that of a bivalve shell; (b) the cardo or basal part of the maxilla in insects.

Conchology and Palaeontology. The hinge of the shell of a bivalve mollusc or brachiopod. Cf. cardinal, adj. 8. Now rare.

= palp, n. Usually in plural.

Zoology. A roundish and flattened part or structure in or on the outside of an animal body. The part of a bivalve shell between the margin and the…

spec. in Conchology. The elastic substance which holds together the valves of a bivalve shell.

Zoology. An appendage in various invertebrate animals, usually paired and located near the mouth, and typically concerned with sensation or feeding…

transferred. A projecting part or point resembling an animal's tooth; esp. one of a row or series of… As a natural structure, in animals, plants…

any one of the teeth or projections on one valve of a bivalve mollusc which fit into corresponding indentations in the other valve.

In those of some bivalves: the projecting apex of each valve, situated directly above the hinge; also called umbo.

Natural History. In bivalve molluscs: the inner pendent margin of the mantle.

transferred. A heel-like part or object. A part of the shell of a bivalve; cf. heel, n.1 10e.

In a bivalve mollusc: the resilient central part of the shell hinge, which tends to force apart the two valves and is composed chiefly of fibrous…

(see quot. 1909).