\[ **BT: [[animals]]** ]
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# molluscs
Members of the phylum **Mollusca**.
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## classification of molluscs
| MOLLUSCA | Subclass | Order | Genus | Species |
| ----------------------- | ------------------------------- | ---------------------------- | ----------------------------------- | ---------------------------------------------------------------- |
| [[#Gastropoda (Class)]] | [[#Caenogastropoda (Subclass)]] | [[#Littorinimorpha (Order)]] | *[[#Crepidula (Genus)\|Crepidula]]* | *[[#Crepidula fornicata (common slipper limpet)\|C. fornicata]]* |
| | | | | |
| Bivaliva | | | | |
| Polyplacophora | | | | |
| Cephalopoda | | | | |
| Scaphopoda | | | | |
| Aplacophora | | | | |
| Monoplacophora | | | | |
| Rostroconchia † | | | | |
| Helcionelloida † | | | | |
[^1]
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## Gastropoda (Class)
![[wellcome collection - 'A variety of gasteropod molluscs, including glaucus, snails and slugs. Line block.' - Public Domain.jpg]]
<small>’A variety of gasteropod molluscs, including glaucus, snails and slugs. Line block.’ via <a href=”https://wellcomecollection.org/works/p2cjufxh”>Wellcome Collection</a>, <a href=”https://creativecommons.org/public-domain/pdm/”>Public Domain</a>.)[^2]</small>
### Caenogastropoda (Subclass)
#### Littorinimorpha (Order)
##### *Crepidula* (Genus)
###### *Crepidula fornicata* (common slipper limpet)
*Crepidula fornicata* is a species of medium-sized sea snail, a marine gastropod mollusc in the family Calyptraeidae, the slipper snails and cup and saucer snails.[^3]
It has many common names, including **common slipper shell**, **common Atlantic slippersnail**, **boat shell**, **quarterdeck shell**, **fornicating slipper snail**, **Atlantic slipper limpet** and it is in Britain as the ‘**common slipper limpet**’.[^3]
[[Slipper limpets (Crepidula fornicata) are sequential hermaphrodites; they ‘first sexually mature as males and later transition to female.’]][^4]
[[Smaller, more mobile slipper limpet (Crepidula fornicata) males join aggregations of larger animals to permanently associate and mate with. When given a choice, a substantial minority of males choose to associate with other males.]][^5]
[^1]: ‘Mollusca’, Wikipedia, last edited 8 January 2026, 05:18 (UTC), https://en.wikipedia.org/wiki/Mollusca#Classification.
[^2]: ‘A variety of gasteropod molluscs, including glaucus, snails and slugs. Line block.’ (Wellcome Collection 41788i), *Wellcome Collection*, \[Origin not identified], accessed 13 February 2025, https://wellcomecollection.org/works/p2cjufxh.
[^3]: ‘*Crepidula fornicata*’, Wikipedia, last edited 17 August 2025, 11:58 (UTC), https://en.wikipedia.org/wiki/Crepidula_fornicata.
[^4]: Julia D. Monk et al., ‘[[Monk et al, ‘An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals’, 2019|An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals]]’, *Nature Ecology & Evolution*, vol. 3, no. 2 (2019), p. 1625, https://doi.org/10.1038/s41559-019-1019-7.
[^5]: Julia D. Monk et al., ‘[[Monk et al, ‘An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals’, 2019|An Alternative Hypothesis for the Evolution of Same-Sex Sexual Behaviour in Animals]]’, *Nature Ecology & Evolution*, vol. 3, no. 2 (2019), p. 1625, https://doi.org/10.1038/s41559-019-1019-7.