NZ Mollusca

Glossary

  • Acicular Needle shaped.
  • Adductor Muscles Anterior and posterior muscles that close a bivalve shell.
  • Anterior Apertural or head end of a gasropod
  • Anterior canal Notch or tubular extension of anterior apertural margin supporting the inhalant siphon.
  • Aperture: Opening of the shell providing outlet for the head and foot. Entrance of the body whorl.
  • Axial Longitudial ribs or colour bands. Parallel to the shells axis.
  • Axis Imaginary line through the apex, about which the whorls are coiled. Central structure of a Gastropod shell.
  • Benthic Bottom dwelling.
  • Body Whorl Last whorl of a univalve/gastropod.
  • Byssus Fibres secreted by foot in bivalves, used for attachment.
  • Canaliculate Gutter-like or channelled. Applied to suture of some Gastropod shells.
  • Cardinal In bivalves, situated more or less in the central part of the hinge area directly below the beaks.
  • Carinate Angled or keeled.
  • Cerata Dorsal appendages in nudibranchs.
  • Chondrophore Pit containing the resilium, a chitinous pad in certain bivalves.
  • Clathrate Latticed by axial and spiral ridges.
  • Columella Apertural part of axis in a spiral gastropod.
  • Concentric Arc-like ridges or striae following the same direction as the ventral margin of a bivalve shell or the growth lines.
  • Dentate Sculptured with teeth or short ridges.
  • Dextral Right hand coiled Gastropod.
  • Divaricate Forked or branched. Diverging sculptural elements, often forming chevrons.
  • Dorsal In gastropods, the side of the shell opposite the aperture. In bivalves, the surface or margin nearest the hinge.
  • Dorsum Back of the shell, opposite the aperture in Gastropods.
  • Escutcheon Depressed area behind ligament in bivalves.
  • Fasciole In Gastropods, either a spiral ridge at base of pillar, or groove on shoulder area, often ending in a sinus.
  • Fimbriate Fringed.
  • Foramen A natural hole or perforation.
  • Fusiform Spindle shaped, Gastropods with tall spire and long canal.
  • Hinge Junction of two bivalve shells, usually characterised by interlocking teeth.
  • Holotype A single specimen upon which a species is based.
  • Imperforate Without an umbilicus.
  • Labrum Outer lip in Gastropods.
  • Lamellae Thin plates or sharply raised ridges.
  • Lectotype A lectotype is a specimen later selected to serve as the single type specimen for species originally described from a set of syntypes. In zoology, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype. Having a single name-bearing type reduces the potential for confusion, especially considering that it is not uncommon for a series of syntypes to contain specimens of more than one species.
  • Lirate Fine raised lines.
  • Lirations Fine raised lines.
  • Lunule Heart shaped depression in front of beaks in bivalves.
  • Mantle Outer edge of molluscan animal that secretes shell.
  • Neotype A specimen later selected to serve as the single type specimen when an original holotype has been lost or destroyed or where the original author never cited a specimen.
  • Nepionic Stage following the embryonic one.
  • Nodose Bearing tubercules or knobs.
  • Operculum In Gastropods
  • Pallial Sinus An indentation or inward bending in the pallial line on the interior of a bivalves valves. Corresponds to the position of the siphons.
  • Paralectotype Any additional specimen from among a set of syntypes, after a lectotype has been designated from among them.
  • Paratype Specimen or specimens from the same lot as the holotype, used in original description of species.
  • Parietal Upper part of inside wall of aperture in Gastropods.
  • Pelagic Swimming or drifting in the open sea.
  • Periostracum Outermost horny covering of a shell
  • Peristome Aperture margin of Gastropod.
  • Plaits Fold on columella or pillar of Gastropods.
  • Prodissoconch Embryonic shell in Bivalves, often preserved at beaks.
  • Protoconch Embryonic shell in Gastropods, often preserved at apex.
  • Pyriform Pear-shaped.
  • Resilium Chitinous pad associated with Bivalve hinge. Causes the shell to open when adductor muscle relaxes.
  • Reticulated Cross ridged, forming network pattern.
  • Rhinophores Pair of club like sensory appendages in nudibranchs.
  • Scalariform Loosely coiled, unwound.
  • Selenizone Spiral band of crescentic growth lines, associated with marginal slit or foramen, in certain univalves.
  • Sinistral Left hand coiled Gastropod, opposite of dextral.
  • Sinus A curve, cleft or indentation.
  • Spatula Spoon-shaped central area of the shell interior of a limpet, usually differing in colour from the rest of interior of the shell. Usually resulting from where the animal was attached to the shell.
  • Spire In Gastropods: all whorls except last one (body whorl).
  • Syntype A syntype is any one of two or more specimens that is listed in a species description where no holotype was designated
  • Teleoconch Entire shell, other than protoconch.
  • Tessellated Checkered pattern, mosaic-like squares.
  • Topotype A biological specimen that is of the same species or subspecies as a type specimen and has been collected from the same location.
  • Umbilicus Gap between reflected inner lip of shell aperture and the first body whorl of Gastropod.
  • Umbo Early part of bivalve shell, often called the beak. Larval shell.
  • Varix A ridge formed at the outer lip in some Gastropods. Left at successive growth stages in some species, and dissolved prior to new growth in other species.
  • Whorl One complete spiral of a Gastropod shell.