| Term | Definition |
| AURIFORM | Shaped like a human ear; used in describing the rhinophores of Hermaea spp.; see also: AURICULATE; HALIOTOID. | |
| AVICULIFORM | [need definition]. | |
| CARDINAL PLATFORM | Shelly internal plate bearing hinge teeth, situated below beak and adjacent parts of dorsal margins and lying in plane parallel to that of commissure; = HINGE PLATE. | |
| CORBULIFORM | Shaped like the shells of the bivalve genus Corbula. | |
| CORDIFORM | Heart shaped, as in the bivalve Corculum cardissa. See also: CORDATE. | |
| CUNEIFORM | Wedge-shaped. | |
| CYATHIFORM | Cup-shaped (as in the "cup" of "cup and saucer" limpets, the Calyptraeidae). | |
| CYPRAEIFORM | A shape exemplified by the gastropod genus Cypraea. See other gastropod shapes. | |
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| DENTAL FORMULA | See: RADULA FORMULA. | |
| DONACIFORM | A form of TRIGONAL shape exemplified by the BIVALVE genus Donax. See other bivalve shapes. | |
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| ECOLOGIC FORM | A morphological condition brought about by the influence of the environment, such as long SPINES in quiet waters; also called: ECOTYPE or ECOPHENOTYPE. See also: FORM or FORMA | |
| ENSIFORM | An ELONGATE bivalve shape, like an Ensis; with outline resembling a curved sword. See other bivalve shapes. | |
| FALCIFORM | Sickle-shaped. | |
| FLABELLIFORM | Fan-shaped. | |
| FORM or FORMA | A minor genetic variant, color phase, aberration, or variation due to diet or environment (e.g., an ECOLOGIC FORM); see also: ECOPHENOTYPE; ECOPHENOTYPIC VARIATION; ECOTYPE; VARIETY. | |
| FUSIFORM |
Spindle-shaped; biconic, i.e., swelling in the central part and tapering at the extremities. See other gastropod shapes. |
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| HAMIFORM | Curved at the extremity; see also: FLEXUOUS; RECURVED; REFLECTED. | |
| HELICIFORM | Shaped like shells of the genus Helix. See also: ESCARGOT. See other gastropod shapes. | |
| INFUNDIBULIFORM | Funnel-shaped, as in the siphon or funnel of a CEPHALOPOD. | |
| LIMACIFORM | [need definition]; used by Abbott, 1974 (pg. 367) in description of Dendronotus. | |
| LINGUIFORM | Tongue-shaped. See also: ELONGATE | |
| LOBIFORM | Lobe-shaped. | |
| MODIOLIFORM | Shaped like the shell of Modiolus spp.; differing from MYTILIFORM in that the BEAKS are not quite terminal and ANTEROVENTRAL region forms slight bulge. | |
| MONILIFORM | Composed of a row of beads, like a necklace; see also: BEADED. | |
| MUSCLE SCAR, CRUCIFORM | [need definition]. | |
| MYTILIFORM |
Shaped like the shell of the genus Mytilus. See other bivalve shapes. Photo: Modiolus modiolus (Linne, 1758) |
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| NERITIFORM | A GLOBOSE GASTROPOD shape resembling that of a Nerite snail (e.g., Nerita spp.; Neritina spp.): with few subglobose and rapidly enlarging whorls with a very reduced SPIRE. See other gastropod shapes. | |
| NUCULANIFORM | A shape exemplified by the bivalve genus Nuculana; = ROSTRATE. See other bivalve shapes. | |
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| PATELLIFORM | Shaped like a human knee cap or patella; = PATELLATE. See other gastropod shapes. | |
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| PECTINIFORM |
[need definition]. Photo: Argopecten irradians concentricus (Say, 1822) |
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| PTERIIFORM |
A shape exemplified by the bivalve genus Pteria. See other bivalve shapes.
Photo: Pteria colymbus (Roding, 1798) |
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| PUPIFORM | Shaped like members of the genus Pupilla [Pupillidae]. See other gastropod shapes. | |
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| PYRIFORM | Shaped like a pear. | |
| RADULA FORMULA |
A series of numbers indicating the number of MARGINAL TEETH, LATERAL TEETH and the RACHIDIAN TOOTH, and (again) the lateral teeth and marginals. Example: a formula of 3+6+R+6+3 indicates 3 marginal teeth, 6 lateral teeth and 1 rachidian (R) tooth. The radula formula may be simply "1" if the radula is UNISERIATE, having only rachidian teeth. See also: DOCOGLOSSATE; STENOGLOSSATE; RHIPIDOOGLOSSATE; TAENIOGLOSSATE; TOXOGLOSSATE. See the excellent illustrations on Wikipedia. |
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| RENIFORM | Shaped like a kidney (e.g., the aperture of Ampullaria spp.). | |
| SCALARIFORM | Loosely coiled; see also: TIGHTLY COILED. | |
| SECURIFORM | Hatchet-shaped. | |
| STROMBIFORM | See: STROMBOID. | |
| TEREDINIFORM |
A shape exemplified by the SHIPWORM bivalve genus Teredo. See other bivalve shapes. Illustration: Teredo sp. (left = entire animal; center = PALLETS; right = shell) |
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| TRAPEZIFORM | With four straight sides, only two of which are parallel; see also: POLYGONAL; QUADRATE. | |
| TROCHOID or TROCHIFORM |
Having the form of a top; conical, with the base of the cone at the APERTURE; see also: TURBINATE. See other gastropod shapes. | |
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| TURRIFORM | Tower-shaped; = TURRICULATE. See other gastropod shapes. | |
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