[Cuvier, 1797]


2. Subclass: ORTHOGASTROPODA Ponder & Lindberg, 1996
[= PROSOBRANCHIA Milne Edwards, 1848 p.p. + OPISTHOBRANCHIA; = AZYGOBRANCHIA Spengel, 1881 p.p.]
  SuperOrder: Caenogastropoda
Order: Hypsogastropoda

SubOrder: Sorbeoconcha

  SuperFamily: Cerithoidea

Family: Thiaridae (Swamp Ceriths)
Freshwater molluscs. The general range of the thiaridae is circum-tropical, and many of the species are extremely widespread. Their dispersal is facilitated by the fact that all are parthenogenic females.


Genus: Melanoides, Ripalania

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Melanoides tuberculata
(Müller, O.F., 1774)
to 21 mm
Family:Cerithiidae (Horn shella)
Their shells are elongate and high spired.They have a short but distinct anterior canal. The sculpture consists of beaded spiral cords, axial ribs and nodules. Size range is quite wide. Form, colour and sculpture is also quite varied. They live in tide pools to depths of approximately 60 meters.
  SubFamily: Species inquirenda
SubFamily: Cerithiinae

Genus: Cerithium, Rhinoclavis, Colina, Plesiotrochus, Gourmya, Clypeomorus, Pseudovertagus, Royella, Clavocerithium, Glyptozaria

Cerithium columna
(Sowerby, G.B. I, 1834)
20 - 40 mm.
Rhinoclavis (Rhinoclavis) gemmata
(Hinds, R.B., 1844)
25 - 40 mm
Colina pinguis
(Adams, A., 1854)
16 mm
Plesiotrochus monachus
(Crosse, H. & P. Fischer, 1864)
24 mm
Gourmya gourmyi
(Crosse, H., 1861)
30 - 75 mm
Clypeomorus batillariaeformis
(Habe, T. & S. Kosuge, 1966)
8 - 25 mm
Pseudovertagus aluco
(Linnaeus, C., 1758) Aluco Vertagus
45 - 95 mm
Royella sinon
(Bayle, C.E., 1880)
30 mm
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SubFamily: Bittiinae

Genus: Bittium, Argyropeza, Cacozeliana, Varicopeza, Ittibittium

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Bittium zebrum
(Kiener, L.C., 1841)
6 mm
Deep Sea Mollusc
Cacozeliana granarium
(Kiener, L.C., 1842)
to 30 mm
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Family: Dialidae
They have a small (approx 2-7mm.) shells. The aperture is complete.

Genus:Finella, Scaliola, Diala, Cerithidium, Mellitestea, Paradiala

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Scaliola bella
(Adams, A., 1860)
to 7 mm
Diala monile
(Adams, A., 1862)
6 - 8 mm
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Family: Diastomatidae

Genus: Diastoma

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Family: Litiopidae

Genus: Litiopa, Alaba

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Alaba incerta
(Orbigny, 1842)

5 mm.
Family: Fossaridae
Shells are small and turbiniform, usually umbilicate and they usually have a prominent protoconch. The last whorl is large, the apertureolbilque, and the columella is connected to the outer lip. Often, spiral sculpture predominates the shells. The operculum is thin and horny, with an upstanding nucleus and open spiral.

Genus: Fossarus, Conradia, Larinopsis

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Fossarus ambiguus
(Linnaeus, 1758)
5 mm.


Family: Modulidae
These shells resemble turban shells, but they are entirely porcelaneous and there is a projecting tooth-like structure at the base of the columella. The aperture is lirate. The operculum is chitinous and multispiral.

Genus: Modulus

Modulus modulus
(Linnaeus, C., 1758)
12 - 17 mm
Family: Obtortionidae

Genus: Obtortio, Eufenella, Clathrofenella

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Family: Potamididae (Horn Shells)
This is a common snail of the mangrove swamps in the Indo-Pacific.

Incertae sedis: Potamides (Pirenella) layardi , Potamides (Pirenella) layardi var bombayanus

Telescopium, Potamides, Cerithidea, Terebralia, Pirenella

Telescopium telescopium
(Linnaeus, C., 1758)
48 - 110 mm
Potamides conicus
(Blainville, H.M.D. de, 1826)
12 - 23 mm
Cerithidea alata
(Philippi, R.A., 1849) 30 mm
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Terebralia semistriata
(Mörch, O.A.L., 1852)
57 mm


Family: Siliquariidae (Worm Snails)
These snails have diverted from a helically coiled shell form, uncoiled completely and have developed into worm-shaped shells that often are cemented to the substratum. These"worm snails" form massive snail reefs that appear to be in global decline. As more-or-less sessile, gill-filtering or slime-net-feeding organisms they fill unusual niches among the gastropods.
Siliquaria anguina
(Linnaeus, C., 1758)
20 - 80 mm.
    Genus: Siliquaria, Stephopoma
Family: Turritellidae (Deep Sea Augers, True Augers)
"Shells of this family are shaped like long, slender augers or screws and resemble Terebridae shells. However, the similarity ends there. The turritella shell shape is somewhat variable, and shells are thin, rough and not lustrous. The rounded mouth and complete absence of a siphonal canal at the anterior end of the aperture clearly identify turritellas. The shells have in addition: a very tall spire; numerous convex whorls; no umbilical opening; absence of folds on the columnella, and a horny, flexible operculum that is supported by flexible bristles. ..." Archerd Collection

Turritella cochlea
( Reeve, 1849)
50 - 63mm

  SubFamily: Turritellinae
  Genus: Turritella, Haustator, Zaria, Archimediella, Colpospira, Gazameda, Maoricolpus, Zeacolpus, Spirocolpus, Neohaustator, Banzarecolpus
SubFamily: Turritellopsinae  
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  Genus: Turritellopsis
Family: Orectospirinae

Orectospira shikokuensis (Yokoyama 1928)
5 mm.


    Genus: Orectospira
Family: Planaxidae
This small (Shell 1.5-2.5cm),relatively common snail grazes on algae on rocky areas. The deep, smooth circular ridges on the shell are quite diagnostic.
Planaxis sulcatus
(Born, I. von, 1780)
18 - 35 mm.
    Genus: Planaxis, Fissilabia, Hinea, Holcostoma, Couthouyia, Angiola, Halotapoda, Simulathena
Family: Batillariidae
The shells are heavy and high-spired, somewhat similar in shape to those of the Cerithiidae, with spiral and axial sculpture, but usually with a flaring outer lip. The animals inhabit estuarine habitats, and are often found in mud between mangroves. Capricornica
Batillaria minima
(Gmelin, 1791)
20 mm.
    Genus: Pyrazus, Batillaria, Zeacumantus, Batillariella, Velacumantus


  SuperOrder: Hypsogastropoda
  Order: Littorinimorpha
  SuperFamily: Littorinoidea
  Family: Littorinidae
"Periwinkles have solidly built shells with typically sharp round protuberances. They are found in intertidal locations widely distributed in most parts of the world, and often in swarms on harbor walls and other rocky surfaces. Some, however, live in mangroves. The outer lip of the shell is sharp-edged and thin, while the mollusc has a horny operculum...." Archerd Shell Collection
SubFamily: Bembiciinae

Bembicium auratum
(Quoy, J.R.C. & J.P. Gaimard, 1834)

20 mm.

  Genus: Bembicium, Risellopsis

SubFamily: Littorininae
Littorina (Littorina) littorea
(Linnaeus, C., 1758)
25 - 43 mm
  Genus: Littorina, Littoraria, Stenotis, Peasiella, Mainwaringia,
Pellilitorina, Nodilittorina, Macquariella, Laevilacunaria,
Rissolittorina, Rufolacuna
SubFamily: Tectariinae

Tectarius (Tectarius) coronatus
(Valenciennes, A., 1832)
40 mm.

  Genus: Tectarius
SubFamily: Laevilitorininae  
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  Genus: Laevilitorina


      SuperFamily: Rissoidea
The shell of the Rissoidea vary in shape and sculpture, but most have a spire higher than the aperture.
Family: Assimineidae
They are small, amphibious, air breathing snails inhabiting brackish water estaries on tropical and semitropical continental coatlines and islands.
Assiminea lutea
Adams, A., 1861
8 mm
Incertae sedis
Assiminea, Omphalotropis, Austroassiminea
Family: Bithyniidae
Small freshwater snails
Bithynia tentaculata
(Limnnaeus, 1758)
8 mm. up
Incertae sedis
Family: Hydrobiidae
Hydrobiids are small to very minute usually conical, operculate fresh or brackish-water snails of considerable antiquity. The family has world-wide distribution.
Mercuria confusa
to 5 mm.

Incertae sedis

Potamopyrgus, Hemistomia, Tatea, Beddomeia, Fluviopupa,
Fluvidona, Jardinella, Phrantela, Posticobia, Ascorhis, Fonscochlea, Trochidrobia

Iravadiidae shells are elongate, always higher than broad and mostly smaller than 5mm. Shells smooth or with spiral sculpture. A diagnostic feature for the family is the planorbid or depressed dome-shaped protoconch, which has two whorls, the first one of which is minute. The animals live in shallow water, mostly in mangrove habitats, some live in brackish water, but some live in deep water. Capricornica
Iravadia (Fluviocingula) elegantula
( Adams A. 1861)
to 3 mm.
    Genus:Ceratia, Iravadia, Rissopsis, Chevallieria, Nozeba,Liroceratia
Family: Stenothyridae
Very small snails which inhabit the brackish water on mudflats
Stenothyra edogawaensis (Yokoyama, 1927)
2 mm
Incertae sedis
Family: Truncatellidae
Inhabit salt marshes and the supra-littoral zone where they live on the surface of mud or under leaf litter
Truncatella pulchella
(Pfeiffer, 1834)
to 6 mm.
    Genus: Truncatella
Family: Rissoidae
SubFamily: Rissoinae
The shell is thin to moderately solid, variously sculptured or smooth. The aperture is shallowly channeled anteriorly and posteriorly
Alvania cancellata
(Costa, E.M. da, 1778)
2 - 5 mm
  Genus:Cingula, Alvania, Onoba, Manzonia, Pusillina, Benthonella,
Merelina, Lironoba, Attenuata , Parashiela, Lucidestea, Powellisetia, Voorwindia
SubFamily: Rissoininae
Shell is tall-spired, usually quite solid and variously sculptured or smaooth The aperture is ovate,typically channeled anteriorly and posteriorly S
Rissoina inca
(Orbigny, A.D. d', 1840)
7 mm.
Rissoina, Zebina, Microstelma, Stosicia, Lamellirissoina
Family: Tornidae
Tornus subcarinatus
(Chaster, 1897)
1 - 2.8 mm
    Genus: Tornus, Laciniorbis, Naricava, Tropidorbis, Uzumakiella
Family: Vitrinellidae
Minute shells which are transparent when the animal is alive but it becomes apaque white after death.The shells are low and flattened, almost always wider than higher. The shells is porcelaneous, umbilicate and often have a collus pad. The protoconch is small and glassy.
Callomphala lucida
(Adams, A. & G.F. Angas, 1864)
1 mm
Vitrinella, Teinostoma, Callomphala, Circulus, Pseudoliotia, Lodderia, Lydiphnis, Scrupus, Anticlimax, Moeniatoma, Ponderinella, Latilabrum
SubFamily: Caecinae
Minute curved shells, sometimes referred to as false tooth shells because of their tubular forms. Caecids start out with a spiral shell but then grow without any further coiling and the tube eventually falls off. They lead a benthic existence in algae-sand flats of tidepools to depths of several hundred meters. The aperture of the adult is circular and there is a horny operculum
Caecum pulchellum
(Stimpson, 1851)
2 mm.
  Genus: Caecum
SubFamily: Pedumicrinae  
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  Genus: Parastropia, Ctiloceras, Jayella, Enigmerces, Ponderoceras
SubFamily: Streblocerinae
These small shells (2-3 mm.) are glossy, translucent, thin, vitreous and cornucopia shaped.
Strebloceras subannulatum
(DeFolin, 1879)
2.6 mm.
  Genus: Strebloceras
Their shells are simple, smooth and typically red-brown. Yhe operculum is thick with a straight peg and longitutdinal thick ridge

Barleeia unifasciata
(Montagu, G., 1803)
1 - 2 mm

    Genus: Barleeia, Protobarleeia
The shells are conical to high-spired and typically possess a pitted protoconch and a chitinous inner shell layer. They live in shallow water on hard substrates.
Photo in Black and White
Pisinna glabrata
(Muhelfedt, 1824)
1 mm.
    Genus: Amphithalamus, Anabathron, Pisinna, Microdryas, Badepigrus, Pseudestea, Afriscrobs
Family: Pelycidiidae  
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    Genus: Pelycidion
Family: Epigridae  
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    Genus: Epigrus
Family: Emblandidae  
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    Genus: Emblanda
Family: Elachisinidae  
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    Genus: Elachisina


      SuperFamily: Cingulopsoidea
The shells of the Cingulopsidae are very minute (not more than 5 mm. in length) They are conical or globular and are tinted with brown.
Family: Eatoniellidae
Small ( 1mm.), simple, conical shells. Their operculum is pegged. They are small algal dwelling molluscs on New Zealand shores where they are micrograzers and microdetrious feeders.
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Family: Rastodentidae
Minute (1-2 mm.) conical shells.They feed on the polyps of zooids and bryozoans. The shells are smooth or spirally corded and the whorls are distinctly margined. The aperture is ovate to circular. They are usually white in colour and highly polished.
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    Genus: Rastodens
Family: Cingulopsidae
Small (not more than 5mm.) conical or globular shells tinted white with brown.
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Eatonina, Eatoniopsis, Tubbreva, Pseudopisinna


      SuperFamily: Stromboidea
  Family: Strombidae (True conchs) They are carnivorous.
"The shells of this family show five unusually distinctive genera, each of which has its own popular name; e.g., Strombus ("conches"), Lambis ("spider shells"), Terebellum ("torpedos"), Tibia ("shinbone shells"), and Varicospira ("beak shells")...."
Archerd Collection
    Genus: Strombus, Lambis, Terebellum, Tibia, Rimella(Varicospira )
Stombus gigas
(Linnaeus, 1758)
to 350 mm
Lambis (Lambis) lambis
(Linnaeus, 1758)
90 - 275 mm
Terebellum terebellum
(Linnaeus, 1758)
32 - 75 mm
Tibia (Tibia) fusus
(Linnaeus, C., 1758)
150 - 310 mm
Rimella crispata
(Sowerby, G.B. I, 1842)
20 - 30 mm
Family: Struthiolariidae (Ostrich Foot Shells) They are filter feeders much like bivalves!
"Ostrich Foot molluscs are almost wholly restricted to New Zealand and parts of Australia. They live in clean water no deeper than about 20 m. and burrow, leaving two openings in the sand above, through which they evidently filter feed. ..." Archerd Collection

Struthiolaria papulosa
(Martyn, T., 1784)
to 80 mm
    Genus: Struthiolaria, Perissodonta, Tylospira
Family: Aporrhaidae (Pelicans Foot)
"Only seven known species of the Pelican's Foot shell have been found, some of which are from the deep sea and rare. The Common Pelican's Foot is found in muddy gravel. All live in cool, boreal, waters. Like the Strombidae, (another family in the superfamily, Strombacea) the Aporrhaidae are actively carnivorous...." Archerd Collection
Aporrhais pespelecani
(Linnaeus, C., 1758)
26- 55 mm.
    Genus: Aporrhais, Drepanocheilus


      SuperFamily: Vanikoroidea
Family: Hipponicidae
Sedentary molluscs which live attached to rocks or other shells. They sometimes leave a distinct cavity in the substrate. The shells are limpet-like and solid with the apex being somewhat posterior and directed backwards. The muscle scar opens anteriorly.
Cheilea cicatricosa
(Reeve, L.A., 1858)
35 mm
    Genus: Cheilea, Sabia, Malluvium, Pilosabia, Antisabia
Family: Vanikoridae
Shell is umbilicate and last whorl is large and globose. The prootoconch is disproportioately small. Apical whorls are strongly sculptured but this sculpture becomes less obsolete on the last whorl. They live under rubble in tidepools or under large coral boulders at moderate depths.
Vanikoro cancellata
(Lamarck, J.B.P.A. de, 1822)
16 - 25 mm

    Genus: Vanikoro, Japanonoba

Family: Haloceratidae



Haloceras trichotropoides
( Warén & Bouchet,1991)
4.2 mm.
    Genus: Haloceras, Zygoceras


      SuperFamily: Calyptraeoidea
Family: Calyptraeidae (Slipper Shells)
"Flat, small to medium-sized, slipper or limpet-shaped shells, which have a plate-like process on the underside of the shell... " Capricornica
Crepidula (Ianacus) fornicata
(Linnaeus, C., 1758)
30 - 56 mm

    Genus: Calyptraea, Crepidula, Crucibulum, Trochita, Clypeola, Sigapatella


      SuperFamily: Capuloidea
Family: Capulidae (Cap Shells)
Most capulidaes have simple, somewhat irregular, cap-shaped shells. They often take the form of the substrate to which they are attached. Some are ciliary feeders while others bore holes into their hosts.
Capulus (Krebsia) ungaricus
(Linnaeus, C., 1767)
15 - 60 mm

    Genus: Capulus, Lippistes, Krebsia, Sirius, Icuncula, Zelippistes


      SuperFamily: Xenophoroidea
Family: Xenophoridae (Carrier Shells)
"These gastropods often decorate their shell by selectively cementing small shells of other gastropods on the dorsal surface, often in fantastic radiating sunburst patterns. Stripped of decorations, the shells are similar in form to some star shell and other species in the Trochacea superfamily. Identifying characteristics of Xenophoridae are an operculum with nucleus off-centered, and, unlike the Trochidae, a shell interior that is not nacreous. The Family has few species. All are tropical in distribution. ..." Archerd Collection
Stellaria solaris
(Linnaeus, C., 1764)
75 - 130 mm

    Genus: Xenophora, Stellaria, Onustus

      SuperFamily: Vermetoidea
Family: Vermetidae (Worm Shells)
"Most Vermetidae gastropods grow in irregular masses...Many of these worm shells actually change their plane of coiling after the first few whorls, such that the spire might end up at a right angle with respect to the later coils... "Archerd Collection
Vermetis alii
(Hadfield, M.G. & E.A. Kay, 1972 )
30 - 40 mm.
Incertae sedis
Vermetus, Serpulorbis, Petaloconchus, Dendropoma, Magilina

      SuperFamily: Cypraeoidea
Family: Pediculariidae

Pedicularia californica
(Newcomb, 1864)
6 mm.
Jenneria pustulata
(Lightfoot, J. in Solander, 1786)
to 27 mm.
    Genus: Pedicularia

Family: Cypraeidae
"A very deep coating of enamel on the outer surface gives the the shell a brilliantly polished appearance, naturally. In life, two lobes of the cowrie's mantle extend out and over the dorsal surface of the shell, meeting at midline, and they continually deposit enamel while protecting the shell from abrasion. Interestingly, the mantle has a totally different color and pattern than the shell. If startled or touched the cowrie can suddenly change colors by withdrawing its mantle completely inside the shell, thus confusing a predator.
Although the shell seems to be bilaterally symmetrical, the newest whorl completely covers the previous whorls. Well developed teeth are found on both sides of the lengthwise aperture slit. Cowries are nocturnal and feed on algae around coral reefs. ..." Archerd Collection

"The animals of the Cypraeidae are nocturnal and hide in crevices during the day. Most are herbivores, although some feed on sponges and bryozoans. The female produces an egg mass or capsules and stays with them until they hatch as veligers. A characteristic of this family is the mantle, which envelops the shell entirely when the animal is in motion and often has a very different colour from the shell...." Capricornica

SubFamily: Cypraeinae
"Large to very large solid shells with narrow apertures and well pruduced, often numerous teeth which are frequently tinted. Produced fossula usually ribbed. Dorsum mostly banded, without any tinting, or spotted and netted in all shades. No species; however has a middorsal blotch. YThe coloration is usually distributed evenly all over the dorsum. Mostly shallow water species with wide distribution and several subspecies...."
A Guide to Worldwide Cowries: by feliz Lorenze & Alex Hubert" Page 51.
J.E. Gray (1824) Zool J., London, Vol 1 P. 71
Genus: Cypraea, Lyncina, Mauritia, Talparia, Luria, Chelycypraea, Leporicypraea


Cypraea tigris schilderiana
Cate, CN, 1961
to 150+ mm.


Lyncina lynx
(Linnaeus, 1758)
to 90 mm.

Talparia) talpa
(Linnaeus, 1758)
to 106 mm.

Mauritia mauritiana
(Linnaeus, 1758)
to 130 mm.

Luria tessellata
(Swainson, 1822)
to 55 mm.

Chelycypraea testudinaria
to 145 mm.

Leporicypraea valentia
(Perry, 1811)
70 100 mm.
SubFamily: Erosariinae
"The shells of Erosaria have variable shape, but are often depressed with angular, usually distincttly pitted margins. The dorsum is covered with spots of varialble structure, the margins are often spotted. The teethe are rather angular, leading to a well-defined terminal ridge bordering the outlet..."
A Guide to Worldwide Cowries: by feliz Lorenze & Alex Hubert" Page 187
F.H. Troschel (1863) Das Gebiss der Schnecken (Berlin), Vol. 1 p. 205, 210.
Genus: Naria, Pustularia, Erosaria, Monetaria, Staphylaea, Ipsa, Annepona, Nucleolaria


Naria irrorata
(Gray, 1828)
to 17 mm.


Pustularia mauiensis
(Burgess, 1967)
to 19 mm.

Erosaria gangranosa
(Dillwyn, 1817)
to 28 mm.

Monetaria moneta

(Linnaeus, 1758)
to 44 mm.

Staphylaea Staphylaea
to 29 mm.


Ipsa childreni
(Gray, 1825)
to 32 mm.

Annepona mariae
(Schilder, 1927)
to 21 mm.

Granulata granulata
(Pease, 1862)
to 49 mm.
SubFamily: Bernayinae
Rather large shells, solid in texture, with shell produced extremities and callous margins. Columellar teeth usually tend to become obsolete midway, they are comletely absent in some fossil and living species. Profusely mottled or characteristically marked dorsum, varying in all shades of color. Bandinf always indistinct and confuse. Fossula smooth and rather reduced. Teeth never extend far into lips..."
A Guide to Worldwide Cowries: by feliz Lorenze & Alex Hubert" Page 33
F.A. Schilder (1927) Arch. Naturgesch., Vol. 91/A10, p.88
Genus: Zoila, Bernaya, Barycypraea

Zoila decipiens
(Smith, 1880)
to 70 mm.

Bernaya teulerei
(Cazanavette, 1846)
to 67 mm.

Barycypraea fultoni
(Sowerby, 1903)
to 72 mm.

SubFamily: Cypraeovulinae
Large group of smaller shells with variable features. Dorsum mainly profusely mottled of regularity spotted and blotched... Most species have a reduced and smooth fossula...."
"A Guide to Worldwide Cowries: by feliz Lorenze & Alex Hubert" Page 33
F.A. Schilder (1927) Arch. Naturgesch., Vol. 91/A10, p.68

  Genus: Cypraeovula, Erronea, Umbilia, Austrocypraea, Bistolida, Notocypraea, Cribrarula, Blasicrura, Palmadusta, Notadusta, Purpuradusta, Nesiocypraea, Chimaeria

A Review of the
Cypraeidae: Cypraeovula

by Felix Lorenz


Cypraeovula) cruickshanki
(Kilburn, R.N., 1972)
to 34 mm.
deep water species

Erronea pulchella pericalles
(Melvill & Standen 1904)
to 40 mm

Umbilia capricornica Lorenz, 1989
to 94 mm.

Austrocypraea reevei
(Sowerby I, 1832)
to51 mm.

Bistolida diauges
(Melvill, J.C., 1888)
to 42 mm.

Notocypraea comptonii mayi
(Beddome, 1898)

Cypraea gaskoinii
to 30 mm.

Palmadusta clandestina moniliaris
(Lamarck, J.B.P.A. de, 1810)
to 26 mm.

Notadusta punctata berinii
Dautzenberg 1906)
to 22 mm.

Purpuradusta fimbriata quasigracilis
(Lorenz, F. Jr., 1989)
to 20 mm.

Nesiocypraea langfordi langfordi
(Kuroda, T., 1938)
to 70 mm.

Chimaeria incomparabilis
(Briano, 1993)
to 93 mm.
Family: Ovulidae (Egg Shells)
"False cowries of the Ovulidae family are members of the same superfamily, as the Cypraeidae. They usually have smaller shells but otherwise resemble the Cypraeidae and share similar mantle protective habits. Archerd Collection

Genus: Ovula, Volva, Calpurnus, Simnia, Neosimnia, Primovula, Prosimnia, Pseudocypraea, Pseudosimnia, Procalpurnus, Diminovula, Phenacovolva, Prionovolva, Margovula, Dentiovula, Habruprionovolva, Kuroshiovolva, Cymbovula, Hiatavolva, Lacrima, Labiovolva, Xandarovula, Aperiovula, Crenavolva, Serratovolva, Stohleroma, Rotaovula, Cuspivolva, Carpiscula, Subsimnia, Simnialena, Spiculata, Dissona, Sandalia, Aclyvolva, Turbovula, Testudovolva, Lunovula


Ovula ovum
(Linnaeus, C., 1758)
to 96 mm.

Volva volva

(Linnaeus, 1758)
to 134 mm.


Calpurnus verrucosus
(Linnaeus, C., 1758)
to 35 mm.


Simnia rufa
(Sowerby, 1832)


Neosimnia spelta
(Linnaeus, 1758)
11 mm. up

Prionovolva pudica wilsoniana (Cate, 1973 )
16 mm. up

Prosimnia semperi
(Weinkauff, 1881)
10 mm. up

Pseudocypraea adamsonii (Sowerby II, 1832)
8 mm. up

Pseudosimnia sinensis
(Sowerby, 1874)
17 mm. up

Procalpurnus lacteus
(Lamarck, 1810)
9 mm. up

Diminovula punctata
(Duclos, 1831)
7 mm. up

Phenacovolva angasi
(Reeve, 1865)
20 mm. up

Primovula formosa
(Adams & Reeve, 1848)
13 mm. up

Margovula schilderorum
( Cate, 1973)
19 mm

Dentiovula dorsuosa
(Hinds, 1844)
11 mm. up
see image
Habruprionovolva manifesta
(Iredale, T., 1936)
9 mm

Kuroshiovolva shingoi
(Azuma, M. & C.N. Cate, 1971)
to 21 mm

Cymbovula massierorum
( Fehse, 1999 )
13 mm.

Hiatavolva brunneiterma
(Cate, 1969)
19 mm. up

unable to locate image

unable to locate image

Xandarovula formosana
(Azuma, M., 1972)

Aperiovula adriatica
(Sowerby, G.B. I, 1828 )
to 25 mm.

Crenavolva striatula
(Sowerby, 1828)
8 mm. up

Serratovolva dondani
(Cate, C.N., 1964)
11 - 16 mm

unable to locate image

Rotaovula hirohitoi
(Cate, C.N. & M. Azuma in Cate, C.N., 1973)
7 mm .

Cuspivolva cuspis
(Cate, C.N., 1973)
9 mm

Carpiscula bullata
(Adams, A. & L.A. Reeve, 1848)
12 mm

unable to locate image


Simnialena uniplicata
(Sowerby, G.B. II, 1848)
12 - 21 mm.


Spiculata loebbeckeana
(Weinkauff, H.C., 1881)
16 mm.

Dissona hasta
Cate, C.N. & M. Azuma in Cate, C.N., 1973

Sandalia triticea
(Lamarck, J.B.P.A. de, 1810)
15 mm.

Aclyvolva lanceolata
(Sowerby, G.B. II, 1848) 20 mm

Turbovula fusula
Cate, C.N. & M. Azuma in Cate, C.N., 1973

Testudovolva orientis
(Cate, C.N., 1973)
7 mm.

unable to locate image


      SuperFamily: Velutinoidea
Family: Lamellariidae
"Lamellariids, or as they now should be called, velutinids,(formerly Family Lamellariidae), are caenogastropod snails, closely related to the Triviidae. In most velutinids the shell is open and flattened, much like a small abalone shell (Haliotidae), and at least partially enveloped by the fleshy mantle. This gives them a fleshy shell-less appearance which often causes them to be mistaken for sea slugs. In most cases when they are crawling a pair of head tentacles will emerge from beneath the body, instantly showing that these are not opisthobranch sea slugs. Another character is the anterior siphon above the head which opens into the mantle cavity.

Velutinids all seem to feed on colonial ascidians and many, like the species illustrated, are well camouflaged by their similar colour. Some species however, including some of the large tropical species of Coriocella, are very brightly coloured. This may be a defensive response, as described for many nudibranchs..." SeaSlug Forum

Lamellaria latens
(Müller, O.F., 1776)
10 - 13 mm
    Genus: Lamellaria, Coriocella, Velutella, Chelyonotus, Onchidiopsis,
Caledoniella, Marseniopsis, Mysticoncha
Family: Triviidae (Bean cowries)
"Triviids have usually been considered relatives of the cowries [Fam: Cypraeidae] but are in fact more closely related to the Velutinidae also known as the Lamellariidae(see above). The inflated cowry-like shell is at least partially enveloped by fleshy mantle lobes, which can give them a fleshy shell-less appearance which often causes them to be mistaken for sea slugs. In most cases when they are crawling a pair of head tentacles will emerge from beneath the body, with basal eyes, instantly showing that these are not opisthobranch sea slugs. Another character is the single anterior siphon above the head which opens into the mantle cavity. Velutinoideans all seem to feed on colonial ascidians..." SeaSlug Forum
SubFamily: Eratoinae
Eratoinae shells are high spired and smooth with only the outer lip expanded and toothed. These are predatory molluscs which feed by boring into the bodies of ascidians and using their proboscis to suck up the content. They are found in temperate and warm seas.
Proterato (Sulcerato) angistoma
(Sowerby, G.B. II, 1832)
to 5 mm

  Genus: Erato, Proterato, Hespererato, Alaerato
SubFamily: Triviinae:
Shells of the subfamily Triviinae are cowry-like in shape, but are sculptured with strong ribs across the whole shell surface. Most are uniformly white or pink, with a few having brown bands or spots.
Trivirostra exigua
(Gray, 1831)
5 mm.

  Genus: Trivia, Triviella, Niveria, Pusula, Dolichupis, Trivellona, Robertotrivia, Discotrivia, Circumscapula


      SuperFamily: Naticoidea
  Family: Naticidae (Moon Shells)
"Moon shells are snail-like globular forms with a half moon shaped aperture. Some flattened, disk-like species also exist. Typically, a thick rib-like callus obscures the umbilicus, and the aperture lip is fringed by a thin sharp edge. In life, mantle flaps from each side cover the shell, protecting its lustrous finish.
These molluscs are largely found in sea floor sand of the tropics, but also in waters beyond the Arctic and Antarctic Circles. They make a living by plowing just below the surface. When they find another mollusc, it is enveloped by their massive foot --often too large to be withdrawn into the shell...." Archerd Collection
SubFamily: Ampullospirinae
Globularia fluctuata
( Sowerby, 1825)
  Genus: Pseudopolinices
SubFamily: Naticinae
Natica (Natica) stellata
(Hedley, C., 1913)
32 mm.
  Genus: Natica, Naticarius, Tectonatica, Cryptonatica, Friginatica, Tanea, Notocochlis, Tasmatica, Glyphepithema
SubFamily: Polinicinae
Polinices (Polinices) aurantium
(Röding, P.F., 1798)
to 45 mm
  Genus: Polinices, Lunatia, Kerguelenatica, Falsilunatia, Sinuber
SubFamily: Sininae
Sinum incisum
(Reeve, L.A., 1864)
35 mm

  Genus: Sinum, Eunaticina, Sigatica, Gennaeosinum


      SuperFamily: Tonnoidea
Family: Bursidae (Frog shells)
Frog shells are distinguished by a deep slot for the posterior siphon ...The shells are heavy and generally have no more than two varices per whorl. This small family is typically found living in or under corals, in tropical and semitropical waters... Archerd Collection
Bufonaria (Bufonaria) margaritula
(Deshayes, G.P., 1832)
25 - 60 mm
    Genus: Bursa, Bufonaria, Tutufa
Family: Ficidae (Fig shells)
Fig shellsare thin, somewhat fig shaped shells. Species in the genus Ficus are mainly found in tropical seas living on sand or mud intertidally or in shallow water, while the recently discovered genus Thalassocyon occurs at abyssal depths.
Ficus ficus
(Linnaeus, C., 1758)
40 - 120 mm
    Genus: Ficus, Thalassocyon
Family: Pisanianuridae
Pisanianura breviaxe
(Kuroda, T. & T. Habe in Habe, T., 1961)
15 - 46 mm
    Genus: Pisanianura
Family: Laubierinidae
The family Laubierinidae was erected in 1990 for three rare, deep water species in the superfamily Tonnoidea. Specimens of all the species are exceptionally rare, only known from a few localities where very deep sea sampling has taken place. URL
Akibumia orientalis
(Schepman, M.M., 1909)
    Genus: Akibumia, Laubierina
Family: Personidae (Distorted whelks)
The Personidae is a small family, only about 25 species, formerly regarded as being part of the Ranellidae. All species in the family are distorted to some extent, due to the necessity for whorls to grow over the expanded varix of the earlier whorl. URL
Distorsio anus
(Linnaeus, C., 1758)
33 - 100 mm
    Genus: Distorsio, Distorsionella, Personopsis, Distorsomina
Family: Ranellidae (Tritons)
The family Ranellidae, previously known as Cymatiidae, are medium to large sized, heavy shells often with multiple varices, covered with a brown periostracum. The family has representatives from the intertidal down to abyssal depths, often with very wide geographical ranges. URL
SubFamily: Ranellinae
Biplex perca
(Perry, G., 1811)
31 - 100 mm
  Genus: Argobuccinum, Gyrineum, Biplex, Ranella, Fusitriton, Halgyrineum
SubFamily: Cymatiinae
Cymatium (Monoplex) pileare
(Linnaeus, C., 1758)
44 - 120 mm
  Genus: Cabestana, Cymatium, Charonia, Sassia
Family: Tonnidae (Tun Shells)
The family Tonnidae includes a small number of species with medium-sized to large shells which are thin for their size, and nearly spherical. The spire is small, while the body whorl is large and well inflated, ending in a very wide aperture. The outer surface is usually sculptured by thick spiral ribs. The animals lack the operculum. Most tun shells can be found living in sand, in the tropics beyond the edge of the coral reef. Archerd Collection
Malea pomum
(Linnaeus, C., 1758)
40 - 80 mm
    Genus: Tonna, Malea, Eudolium
Family: Cassidae (Helmet Shells)
The Helmet Shells are heavily constructed, large or medium size shells with a rather short spire and a well-developed final whorl. The body whorl is voluminous, and often ornamented with knobs and varices (lengthwise ribs). The callus is well developed and extends over the entire ventral surface. Coarse teeth on the inner side of the lip and several prominent columellar folds are common, but not invariable.
Defining characteristics are: outer lip thickened and recurved on the dorsal surface to form a prominent helmet-like rim; and, a short syphonal canal bent backwards and opening toward the dorsal surface. The Family contains eighty or more living species that live in warm waters around the world.

Archerd Collection
SubFamily: Cassinae
Cassis cornuta
(Linné, 1758)
95 - 390 mm
  Genus: Cassis, Galeodea, Cypraecassis
Semicassis (Semicassis) bisulcata
(Schubert & A.J. Wagner, 1829)
25 - 80 mm
  Genus:Phalium, Semicassis, Casmaria, Echinophoria
SubFamily: Oocorythinae
Oocorys alcocki
(Smith, E.A., 1906)
50 - 115 mm
  Genus: Oocorys, Hadroocorys


      SuperFamily: Carinoidea

Family: Atlantidae
Very small 10 mm and under
The numerous Recent species of Atlanta are difficult to identify because of their very small and similar shells, URL
This bizarre little pelagic snail has a transparent, coiled shell into which the body can be completely withdrawn. Due to its small size (shell diameter to 4 mm) and relatively transparent body, is easy to overlook. The ventrally placed slender fin, which has a distinct sucker, is used for swimming. Because of the shell, however, they are relatively inefficient swimmers, and must use continuous jerking movements of the fin to stay in position... URL

Atlanta brunnea
Gray, J.E., 1850
to 2 mm
    Genus: Atlanta, Oxygyrus

Family: Carinariidae
Carinariidae are beautiful animals with a reduced shell in which the soft parts do not fit. In life position the transparant shell is seen below the animal. URL
Few gelatinous animals can match the strangeness of this pelagic snail. Sporting a muscular ventral fin, it swims upside down in search of planktonic prey such as salps, doliolids, copepods, euphausids and chaetognaths. URL

Carinaria lamarcki
( Péron & Lesueur, 1810)
75 mm
    Genus: Carinaria, Cardiapodia

Family: Firolidae
The monotypic genus Firoloida, with type species F. desmaresti Lesueur, 1817 is found in tropical and subtropical areas of all oceans. Firoloida also is not yet known as a fossil. The protoconch of this species is beautifully granulated. URL
You'll need to look very closely to find this transparent heteropod. Except for food in the gut and black pigment in the eyes, this species is nearly invisible. The elongate body lacks a shell, a trait typical of pterotracheid heteropods...URL

Firoloida desmaresti
(Lesueur, 1817)
to 40 mm.
    Genus: Firoloida

Family: Pterotracheidae
Adult Pterotrachea species have no shell and thus are exclusively known from the recent fauna.URL

Anyone searching for techniques to become invisible should study this heteropod. The transparent body is very difficult to see, revealed only by the opaque gut and pair of eyes. The body is elongate and cylindrical in cross section, with a length up to 30 cm but usually far less. A significant portion of the length is made up of an elongate filament extending from the tail. A shell is totally lacking...URL

    Genus: Pterotrachea


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