|Above: In a gastropod, towards the
Adpressed: Joined by overlapping; the opposite to impressed.
Anal canal: A canal, normally open, at the upper (or posterior) end of the gastropod aperture, through which solid waste matter is voided.
Ancillid groove: A spiral groove below the centre of the body whorl on ancillid shells.
Angulation: Formed from corners; angled.
Anterior: At or towards the front or head end of a shell.
Anterior canal: An open or closed tubular shell extension at the anterior end of a shell, through which the siphon is extended. Same as siphonal canal
Aperture: The major opening of a gastropod shell.
Aperture entire: Uninterrupted; without an anterior notch.
Apex: The tip of the spire.
Apical whorls: Those whorls near the apex.
Axial: Pertaining to or more or less parallel to the axis of coiling of a gastropod shell.
Axial sculpture: Sculpture running parallel to the axis in a gastropod shell.
Axis: An imaginary line through the apex of a gastropod shell, about which the whorls are coiled.
Basal: Pertaining to the base.
Basal margin: In a gastropod shell, the angled portion of the body whorl separating the base from the remainder of the whorl.
Base: In coiled gastropods, the zone below the periphery of the body whorl.
Bead: A small, more or less hemispherical protuberance resembling a bead. Beads are smaller than nodules.
Beaded: Sculptured so as to resemble beads, or strings of beads.
Below: In a gastropod, situated more towards the anterior end.
Benthic: Living on the seabed
Bifid: Having two parts.
Body whorl: The most recently formed whorl of a gastropod shell, terminating in the aperture.
Bottom: In a gastropod shell, the anterior end.
Calcareous: Made of, or mostly, calcium carbonate.
Callus: Calcareous thickening
Canaliculate: Prominently grooved; channelled.
Cancellate: A sculpture produced by axial ribs crossed by spiral ribs of about the same size and spacing, giving a lattice-like appearance. Latticed.
Carinate: DONT USE. Use 'keeled'
Columella: A pillar surrounding the axis around which the shell is coiled, formed by the inner surface of the whorls. The wall opposite the outer apertural lip.
Columellar: Pertaining to the columella.
Columellar deck: In nerites, the area on the ventral surface of the shell covered by the columellar callus.
Columellar pillar: The lower end of the columella, particularly in ancillid shells.
Columellar shield: A plate of callus, most evident in the family Cassidae, extending from the columella onto the ventral shell surface.
Concentric: DONT USE. Use 'spiral'
Congeneric: In the same genus.
Conspecific: The same species.
Cord: DONT USE. Use rib, riblet or thread.
Corneous: Made of horny material.
Coronate: With tubercules or nodules around the shoulders of the whorls
Crenulate: Having a regularly notched or scalloped edge.
Decollate: With the apex broken off.
Denticle: A small tooth-like projection.
Dextral: Coiled with a right hand spiral. i.e. clockwise when viewed from the apex.
Dorsal: Of, pertaining to, or situated on the back or upper surface; in a gastropod shell, opposite the aperture. Opposite to ventral.
Dorsum: The dorsal surface of a shell.
Endemic: Peculiar to a region
Entire: Continuous; having no breaks. When applied to the aperture of a gastropod, the aperture in not interrupted by an anterior or posterior canal.
Eroded: Worn away.
Fasciolar band: Fasciole
False umbilicus: An umbilicus-like opening found in some gastropods, but not the true umbilicus.
Fasciole: A raised spiral band near the anterior end of some gastropod shells, formed by successive edges of the anterior canal.
Fenestrate: Literally, windowed; having a sculpture of crossed axial and spiral ribs or riblets, forming rectangular pits as in a multi-pane window.
Flaring: Opening or spreading outwards; said especially of the outer lip of the aperture.
Fold: A major constriction or gathering of the shell surface.
Foliaceous: With thin, leaf-like lamellae.
Foot: The muscular ventral part of the gastropod body used for locomotion.
Fossula: A pit or depression on the anterior part of the inner lip.
Frond: A foliaceous, leaf-like extension of a sculptural element, as on a varical spine
Funicle: Spiral ridge running into the umbilicus.
Fusiform: Spindle shaped; swollen at the centre and tapering almost equally towards the ends.
Granulose: Grainy or finely pustulose; covered with granules.
Growth line: More or less axial line representing former resting position of the outer lip.
Height: Distance from the apex to the anterior tip of a gastropod shell. Also called length.
Heterostrophic: The protoconch coils in a different direction to the rest of the shell; usually applies to the protoconch coiling sinistrally and the teleoconch dextrally.
Holotype: The single specimen designated as the type by the original author of a species name at the time of the original description.
Homonym: One of two or more identical but independently proposed names for different species, genera or taxa.
Imbricated: With scales overlapping each other like roof tiles.
Impressed: Joined by forming a groove; opposite to adpressed.
Inner lip: The lip of the aperture closest to the axis of coiling of a gastropod shell. (Not the inside of the outer lip).
Intertidal: Living between high and low tide levels.
Intervarical: Between the varices.
Keel: A sharply raised ridge, with parallel sides, as in the keel of a ship.
Lamella: (Pl. lamellae). A thin plate or scale, more or less erect. See also scales.
Latticed: Having a sculpture of crossed axial and spital ribs or riblets, not necessarily at right angles.
Lira: (Pl. lirae). A ridge on the shell surface within the aperture of a gastropod shell.
Lirate: With lirae.
Liration: DONT USE. USE Lirae.
Littoral: The zone of the shore between high and low tide levels.
Maculate: Patterned with regular or irregular patches. ie with maculations.
Mantle: The thin skin-like organ which covers the body mass of molluscs and contains the shell-secreting glands.
Mantle line: The line on the dorsal surface of a cowry shell where the mantle lobes meet.
Nacreous: With a layer of nacre, or mother-of-pearl.
Nodule: A rounded protuberance; larger than a bead.
Nodulose: Bearing rounded protuberances.
Oblique: Slanting; inclined from the horizontal or vertical.
Obsolete: Slight, barely apparent.
Operculum: The corneous or calcareous structure attached to the posterior end of the foot of many gastropod shells that closes the aperture when the animal withdraws into the shell.
Opisthocline: Refers to the slope of the outer lip of a gastropod shell sloping backwards in relation to the direction of shell growth.
Orthocline: Refers to the slope of the outer lip of a gastropod shell being parallel to the shell axis, not sloping forward (prosocline) or backwards (opisthocline).
Outer lip: The lip of the aperture of a gastropod shell furthest from the shell axis. The outer lip itself has inner and outer surfaces.
Paratype: A specimen other than the holotype which was seen and designated by the author at the time of the original description of a species or subspecies.
Parietal: Pertaining to the parietal region.
Parietal shield: A calloused area found in some gastropod shells, covering the parietal wall.
Parietal wall: the region of a gastropod shell that extends from the columella around the top of the aperture to the outer lip.
Pelagic: Living on the surface of the sea or in the water column; opposite to benthic.
Penultimate: Second last.
Periostracum: Outer layers of horny material covering the calcareous shell. May be thin and transparent or thick, fibrous or hairy.
Periphery: The part of a gastropod shell farthest from the axis of coiling.
Peristome: The lips or margin of the aperture of a gastropod shell.
Plait: Spiral fold or ridge on the columella. Plica.
Planispiral: Coiled in a single plane.
Planktonic: Drifting or weakly swimming in the ocean.
Planktotrophic: Refers to planktonic larval development where the larvae feeds on micro-organisms and development time in the plankton is long.
Plica: (pl. plicae). A columellar fold.
Plicate: Folded or twisted; having plicae.
Porcellaineous: Polished; surface and texture as in porcelain.
Posterior: The tail end of an animal; in a gastropod shell, towards the apex .
Posterior canal: Anal canal.
Preoccupied: refers to a name which cannot because it was used for another taxon, or was not validly introduced..
Primary: Of the first order; most dominant or conspicuous.
Proboscis: An extensible snout, usually with the mouth at its end.
Produced: Drawn out; elongated; extended.
Prosocline: Referring to the outer lip of a gastropod shell, leaning forward in relation to the direction of growth.
Protoconch: Embryonic shell, present in the adult as the apical or nuclear whorls and often demarcated from the teleoconch whorls by a change of sculpture.
Punctate: Minutely pitted.
Pustulose: With pimple-like or blister-like swellings
Recurved: With the end bent away from the shell axis.
Reflected: Turned outwards and backwards.
Reticulate: Lines, riblets, threads or grooves crossing each other like a net.
Rib: An elongate sculptural element of a shell, raised above the surrounding surface. A fine rib is a riblet, and a very fine rib is a thread.
Riblet: A small rib, but coarser than a thread.
Rugose: Rough; covered with wrinkles, folds or creases.
Scabrous: Covered with scales
Scale: Thin plate-like structures, more or less parallel to the shell surface, as in fish scales.
Secondary: Of the second order; less dominant or conspicuous than primary structures.
Serrate: Notched or toothed at the edge like a saw.
Shoulder: The region of each whorl of a gastropod shell showing a sharper angulation or greater convexity than the rest of the whorl.
Shouldered: Having a shoulder.
Sinistral: Coiled in a left-handed spiral. i.e. anticlockwise when viewed from the apex.
Sinuate: Curved in and out; wavy; tortuous.
Sinus: A deep indentation or cavity
Siphonal canal: An open or closed tubular shell extension at the anterior end of a shell through which the siphon is extended. Same as anterior canal.
Spatula: Spoon-shaped area at the centre of the interior of a limpet shell.
Spicule: A small, slender, needle-like spine.
Spinose: Bearing many spines.
Spiral sculpture: Sculpture following the helical growth of a gastropod shell.
Spire: All whorls of a spiral shell exclusive of the body whorl.
Stria: (Pl. striae). Narrow and shallow incised groove.
Striate: Marked with striae.
Subfossil: A fossil that is younger than what would be considered typical fossil age. i.e. preserved since about 10,000 years ago, but not strictly recent or present day.
Sublittoral: Below low tide level.
Subspecies: A geographically defined group of populations comprising individuals which possess characteristics distinguishing them from other such subdivisions of the species.
Substrate: The material of the sea bed.
Subsutural: Below (i.e. anterior to) the suture.
Suture: The continuous spiral line of junction of whorls of a gastropod shell.
Synonym: Each of two or more different names for the same species or other taxon.
Syntype: One of several type specimens where none has been designated as a holotype.
Teleoconch: All the whorls of a gastropod shell after the protoconch.
Tertiary: Of the third order; generally used for minor sculptural elements.
Thread: A very fine sculptural element of a shell, raised above the surrounding surface. Finer than a rib.
Top: In a gastropod shell, the posterior end.
Truncate: Cut off at the end, blunt.
Turreted: With the spire whorls like a succession of turrets, emerging one above the other.
Type locality: Locality at which the type specimen was collected.
Umbilicus: Cavity or hollow around the axis of a gastropod shell, formed when the inner walls of successive whorls do not meet.
Varical: Pertaining to a varix.
Varix: (Pl. varices). A thickened axial ridge in a gastropod shell, formed by thickening of the outer lip at a resting stage in the growth of the shell.
Ventral: Of, pertaining to, or situated on, the lower side of a dorsiventral organism; on the apertural surface of a gastropod shell. Opposite to dorsal.
Whorl: A single, complete turn of 360º in the spiral growth of a gastropod shell.