= onycha, n., onyx, n. 2. Obsolete.

Zoology. In molluscs, cirripedes, and brachiopods: the layer of epidermal tissue which encloses the body and secretes the shell. Also: any of…

The proboscis of some molluscs; also the proboscis of various insects. Now rare or Obsolete.

Zoology. A septum or partition separating the successive chambers of certain shells. Also applied to the operculum of a gastropod.

Botany and Conchology. = operculum, n.

Zoology. The calcareous, horny, or fibrous plate secreted by some gastropod molluscs, esp. prosobranchs, which serves to close the aperture of…

Botany and Zoology. An outgrowth on a plant or animal, typically at the side; spec. a wing-like projection towards the hinge of the shell of a…

Zoology. Any of various filaments, bristles, or appendages on an animal thought to resemble a beard… The byssus or tuft of fine filaments by which…

Zoology. That part of an insect which lies between the head and abdomen; the thorax. Also applied to an external structure on the thorax of some…

Natural History. A mark or trace indicating the point of attachment of some structure that has been removed; Botany and Conchology = cicatrix, n. 2 3.

Zoology and Botany. An operculum.

Zoology and Palaeontology. A lateral part in various invertebrate structures; spec. (a) a pleuron or pleurite of an arthropod, esp. a trilobite; (b)…

Zoology. The mantle of a mollusc or brachiopod (mantle, n. 8).

Zoology. The tuft of fine silky filaments by which molluscs of the genus Pinna and various mussels attach themselves to the surface of rocks; it is…

Of or pertaining to the head, situated in the head; of the nature of a head. Physiology and Biology.

An operculum.

the odontophore or radula of a mollusc.

Anatomy and Zoology. One of the siphons of a mollusc.

The mantle, n. or pallium, n. of molluscs.

Zoology. The shell of certain invertebrates.

Zoology. In Molluscs: A thickened muscular and glandular border of the mantle.

Zoology. The shell of certain invertebrates: = test, n.2 2a. Obsolete. rare.

Zoology. In a gastropod mollusc: the central or axial part of the radula, typically bearing a median row of teeth (cf. rachidian, adj. n.). Now rare.

A hook-shaped part or process; esp. one of the hook-like teeth of molluscs.

a terrestrial mollusk or its shell.

the space enclosed between the mantle and the body of a mollusc, brachiopod, etc., containing respiratory organs.

Zoology. The middle lobe of the foot of a mollusc.

The anterior lobe of the foot in some molluscs, esp. gastropods.

Zoology. The movable rasping structure in the mouth of many molluscs, bearing chitinous teeth and used for scraping off and drawing in food particles.

humorous. The substance of a mollusc. Obsolete. rare.

(in molluscs) an organ consisting of a series of filaments borne on an axis suspended within the mantle cavity; = ctenidium, n.

= mantle cavity n. at mantle, n. compounds 2.

one of the teeth of the odontophore of a mollusc.

= mesopodium, n. 1.

A movable ribbon-like cartilaginous projection in the mouth of a mollusc on which the rasping organ or radula is supported. Also (occasionally)…

= mantle cavity n. at mantle, n. compounds 2.

(a) an excretory organ beneath the shell in the lower crustaceans; (b) the shell-secreting gland of a mollusc.

Zoology. The radula of a mollusc; an individual tooth on this. Also: the rasping tongue of a lamprey. Now rare.

A primitive, typical, or unmodified foot.

Each of the respiratory organs or gills of Mollusca, consisting of an axis with a series of processes on each side like the teeth of a comb.

An olfactory organ in some gastropod molluscs, consisting of an area of sensitive tissue on the gill membranes.

= shell-gland n. (b).

the lingual ribbon or odontophore of certain molluscs.

In a chiton: any of the numerous photoreceptive sensory structures distributed in megalopores over the surface of the valves.

Zoology. A rachidian tooth of a gastropod mollusc.

A mollusc or conch, esp. the meat of a mollusc eaten as a delicacy.

the sheath-like structure surrounding the base of the tentacles of many molluscs.