{{Short description|Family of gastropods}} {{Automatic taxobox | image = Georissa shikokuensis 001.jpg | image_caption = ''Georissa shikokuensis'' | parent_authority = Troschel, 1857 | taxon = Hydrocenidae | fossil_range = {{fossilrange|Cenomanian|Present}} | authority = Troschel, 1857 | synonyms = Georissinae Blanford, 1864 }}
'''Hydrocenidae''' is a taxonomic family of minute land snails or '''cave snails''' with an operculum, terrestrial gastropod mollusks or micromollusks in the clade Cycloneritimorpha.
Hydrocenidae are widespread across the Palearctis and Africa, but reach their highest diversity in the Oriental, Australian, and Oceanian regions. The family is poorly known and has not been revised in the past 140 years and as a consequence, the status of the various genus names (including ''Georissa'') is uncertain.
Hydrocenidae is the only family in the superfamily '''Hydrocenoidea'''. This family has no subfamilies according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005.
== Description == The animal have no gill, but a pulmonary cavity.<ref name="Suter 1913"/> Tentacles are short and large.<ref name="Suter 1913"/> The eyes are prominent, situated at the upper or outer base of the tentacles.<ref name="Suter 1913"/> The foot is short, oval and obtuse.<ref name="Suter 1913"/> The denticle (tiny teeth) of radula have the formula ∞ 1, (1 + 1 + 1), 1 ∞.<ref name="Suter 1913"/> The central denticles are small and elongated.<ref name="Suter 1913"/> The lateral tooth is rather large, straight, without a cusp.<ref name="Suter 1913"/> The numerous lateral teeth are denticulate, and arranged in very oblique series.<ref name="Suter 1913"/>
The shell is imperforate, conic and globular.<ref name="Suter 1913"/> Whorls are convex.<ref name="Suter 1913"/> The spire is short.<ref name="Suter 1913"/> The peristome is continuous.<ref name="Suter 1913"/> The columella is callous.<ref name="Suter 1913"/> The lip is not reflexed.<ref name="Suter 1913"/> The operculum is calcareous, ornamented with striae which are concentric to the nucleus.<ref name="Suter 1913"/> The inner side of the operculum is with a prominent apophysis arising from the nucleus.<ref name="Suter 1913"/>
== Genera == Genera and species within the family Hydrocenidae include:<ref>{{ITIS |id=70201 |taxon=''Hydrocena''}}</ref> * Genus ''Georissa'' Blanford, 1884 * Genus ''Hydrocena'' Pfeiffer, 1841 ** ''Hydrocena cattaroense'' (Pfeiffer, 1841) **''?Hydrocena praecursor'' Tingting and Neubauer, 2021 Burmese amber, Myanmar, Cenomanian<ref>{{Cite journal|last1=Tingting|first1=Yu|last2=Neubauer|first2=Thomas A.|date=January 2021|title=The oldest fossil Hydrocenidae found in mid-Cretaceous Burmese amber (Gastropoda: Cycloneritida)|url=https://linkinghub.elsevier.com/retrieve/pii/S0195667121000124|journal=Cretaceous Research|volume=122 |language=en|article-number=104765|doi=10.1016/j.cretres.2021.104765|s2cid=233585283 |url-access=subscription}}</ref> * Genus ''Omphalorissa'' Iredale, 1933 ** ''Omphalorissa purchasi'' (Pfeiffer, 1862) * ''Monterissa'' Iredale, 1944 ** ''Monterissa gowerensis''
==References== {{Commons category|Hydrocenidae}} This article incorporates public domain text from the reference.<ref name="Suter 1913">Suter H. (1913). ''Manual of the New Zealand Mollusca''. Wellington, 1120 pp. [https://archive.org/stream/manualofnewzeala00sute#page/174/mode/2up/ page 175].</ref> {{Reflist}}
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Category:Hydrocenidae Category:Cave snails Category:Neritimorpha