Terminology Description
Terminology Description
Above In a gastropod, towards the posterior end.
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.
Denticulate Toothed.
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.
Papillate Teat-like
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.
Sympatric ???????
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.