Helix (genus)

''Helix'' is a genus of large, air-breathing land snails native to Europe and the Mediterranean region. They are the type genus of the family Helicidae, and are among the first animal genera described by Carl Linnaeus.Rosenberg, G.; Bouchet, P. (2014). ''Helix'' Linnaeus, 1758. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153970 on 2015-02-24 Members of the genus first appeared during the Oligocene. Like most land snails, ''Helix'' species are hermaphroditic, and like other helicids, a courting pair will impale each other with hormone-rich love darts prior to exchanging sperm. Well-known species include ''Helix pomatia'' (Roman snail, Burgundy snail, or edible snail) and ''Helix lucorum'' (Turkish snail). '' Cornu aspersum'' (garden snail) – another well-known helicid – was originally described as a member of ''Helix'' (as "''Helix aspersa''"), but the prevailing classification places it as the sole member of the sister genus ''Cornu''.

''Helix'' snails have been harvested for human consumption since prehistoric times. In the common era, members of the genus (particularly ''H. pomatia'') are farmed throughout the world for the dish escargot, an ''hors d'oeuvre''. The establishment of snail farms outside of Europe has introduced several species to North America, South America, and Africa, where some escapees have established themselves as invasive species.

Taxonomy

Some taxonomists remove the species "''Helix aperta''", "''Helix aspersa''", and "''Helix mazzullii''" from the genus ''Helix'' and place them in their own monotypic genera as ''Cantareus apertus'', ''Cornu aspersum'', and ''Cantareus mazzullii''.

At the beginning in the mid-1700s, the generic name ''Helix'' had been used for almost all terrestrial gastropods; later this was restricted to species with helicoid habitus, including zonitids and other groups. In the course of the 1800s, more groups were removed, but prior to 1900, several thousand helicid and hygromiid species of Europe and abroad had still been classified in the genus ''Helix''. By the early 1900s, the genus was split into many separate genera, leaving only some 30 species closely related to its type species ''Helix pomatia'' in the genus.

The genus ''Helix'' has many synonyms:
* ''Callunea'' Scudder, 1882
* ''Cochlea'' Da Costa, 1778
* ''Coenatoria'' Held, 1838
* ''Cunula'' Pallary, 1936
* ''Glischrus'' S. Studer, 1820
* ''Glischrus (Helix)'' Linnaeus, 1758
* ''Helicites'' W. Martin, 1809 (Established for fossils of Helix to distinguish them from extant members of that taxon. Invalid: available only for the purposes of the Principle of Homonymy (Art. 20))
* ''Helicogena'' A. Férussac, 1821
* ''Helix (Helix)'' Linnaeus, 1758· accepted, alternate representation
* ''Helix (Pelasga)'' P. Hesse, 1908· accepted, alternate representation
* ''Megastoma'' Scudder, 1882
* ''Naegelea'' P. Hesse, 1918
* ''Pachyphallus'' P. Hesse, 1918
* ''Pentataenia'' A. Schmidt, 1855 (junior objective synonym)
* ''Physospira'' C.R. Boettger, 1914
* ''Pomatia'' Beck, 1837
* ''Pomatiana'' Fagot, 1903
* ''Pomatiella'' Pallary, 1909
* ''Pseudofigulina'' P. Hesse, 1917
* ''Rhododerma'' P. Hesse, 1918
* ''Tacheopsis'' Boettger, 1909
* ''Tammouzia'' Pallary, 1939

Many species of ''Helix'' have been brought into synonymy:
* ''Helix achates'' Rossmässler, 1835: synonym of ''Chilostoma achates'' (Rossmässler, 1835)
* ''Helix afra'' Gmelin, 1791: synonym of ''Pedipes pedipes'' (Bruguière, 1789)
* ''Helix amarula'' Linnaeus, 1758: synonym of ''Thiara amarula'' (Linnaeus, 1758)
* ''Helix ambigua'' Linnaeus, 1758: synonym of ''Fossarus ambiguus'' (Linnaeus, 1758)
* ''Helix ampullacea'' Linnaeus, 1758: synonym of ''Pila ampullacea'' (Linnaeus, 1758)
* ''Helix aorangi'' Suter, 1890: synonym of '' Huonodon microundulatum'' (Suter, 1890)
* ''Helix auricularia'' Linnaeus, 1758: synonym of ''Radix auricularia'' (Linnaeus, 1758)
* ''Helix australis'' Férussac, 1821: synonym of '' Austrosuccinea australis'' (Férussac, 1821)
* ''Helix cingulata'' (Studer, 1820): synonym of ''Chilostoma cingulatum'' (Studer, 1820)
* ''Helix cingulata'' var. ''olympica'' Roth, 1855: synonym of ''Cattania olympica'' (Roth, 1855)
* ''Helix complanata'' Linnaeus, 1758: synonym of ''Hippeutis complanatus'' (Linnaeus, 1758)
* ''Helix contorta'' Linnaeus, 1758: synonym of ''Bathyomphalus contortus'' (Linnaeus, 1758)
* ''Helix corallina'' Chemnitz, 1795: synonym of '' Scalenostoma subulatum'' (Broderip, 1832)
* ''Helix coriacea'' Pallas, 1788: synonym of '' Velutina coriacea'' (Pallas, 1788)
* ''Helix cornuarietis'' Linnaeus, 1758: synonym of ''Marisa cornuarietis'' (Linnaeus, 1758)
* ''Helix corvus'' Gmelin, 1791: synonym of '' Corvusiana corvus'' (Gmelin, 1791)
* ''Helix crenata'' Gmelin, 1791: synonym of ''Amphibola crenata'' (Gmelin, 1791)
* ''Helix cyclostomoides'' Pfeiffer, 1840: synonym of '' Vitrinella cyclostomoides'' (Pfeiffer, 1840)
* ''Helix decussata'' Montagu, 1803: synonym of '' Rissoina decussata'' ( Montagu, 1803)
* ''Helix depressa'' Montagu, 1803: synonym of ''Skeneopsis planorbis'' (O. Fabricius, 1780)
* ''Helix eburnea'' Mühlfeld, 1824: synonym of '' Melanella eburnea'' (Mühlfeld, 1824)
* ''Helix fasciata'' Adams J., 1800: synonym of ''Lacuna parva'' (da Costa, 1778)
* ''Helix fasciolata'' Spix in Wagner, 1827: synonym of ''Asolene crassa'' (Swainson, 1823)
* ''Helix flavocincta'' Mühlfeld, 1829: synonym of ''Eulima glabra'' (da Costa, 1778)
* ''Helix fossaria'' Montagu, 1803: synonym of ''Galba truncatula'' (O. F. Müller, 1774)
* ''Helix fragilis'' Linnaeus, 1758: synonym of ''Lymnaea fragilis'' (Linnaeus, 1758)
* ''Helix fulgidus'' Adams J., 1797: synonym of ''Eatonina fulgida'' (Adams J., 1797)
* ''Helix glabrata'' Megerle von Mühlfeld, 1824: synonym of '' Pisinna glabrata'' (Megerle von Mühlfeld, 1824)
* ''Helix glauca'' Linnaeus, 1758: synonym of ''Pomacea glauca'' (Linnaeus, 1758)
* ''Helix grenvillei'' Brazier, 1876: synonym of ''Thysanota grenvillei (''Brazier, 1876)
* ''Helix haliotoidea'' Linnaeus, 1758: synonym of ''Sinum haliotoideum'' (Linnaeus, 1758)
* ''Helix janthina'' Linnaeus, 1758: synonym of ''Janthina janthina'' (Linnaeus, 1758)
* ''Helix janthina'' Linnaeus, 1764: synonym of ''Janthina prolongata'' Blainville, 1822: synonym of ''Janthina globosa'' Swainson, 1822
* ''Helix labiosa'' Montagu, 1803: synonym of '' Rissoa membranacea'' (J. Adams, 1800)
* ''Helix lacuna'' Montagu, 1803: synonym of ''Lacuna parva'' (da Costa, 1778)
* ''Helix laevigata'' Linnaeus, 1758: synonym of '' Velutina velutina'' (O. F. Müller, 1776)
* ''Helix littorina'' delle Chiaje, 1828: synonym of ''Paludinella littorina'' (delle Chiaje, 1828): synonym of '' Melarhaphe neritoides'' (Linnaeus, 1758)
* ''Helix macneili'' Crosse, 1873: synonym of '' Averellia macneili'' (Crosse, 1873)
* ''Helix margarita'' Montagu, 1808: synonym of ''Margarites helicinus'' (Phipps, 1774)
* ''Helix mespillum'' Mühlfeld, 1824: synonym of '' Echinolittorina mespillum'' (Mühlfeld, 1824)
* ''Helix neritina'' Gmelin, 1791: synonym of ''Pomacea glauca'' (Linnaeus, 1758)
* ''Helix neritoidea'' Linnaeus, 1758: synonym of '' Sinum neritoideum'' (Linnaeus, 1758)
* ''Helix neritoidea'' Gmelin, 1791: synonym of ''Lamellaria perspicua'' (Linnaeus, 1758)
* ''Helix nutans'' Mühlfeld, 1824: synonym of '' Melanella nutans'' (Mühlfeld, 1824)
* ''Helix oculuscommunis'' Gmelin, 1791: synonym of ''Pomacea glauca'' (Linnaeus, 1758)
* ''Helix otis'' Turton, 1819: synonym of '' Otina ovata'' (Brown, 1827)
* ''Helix paradoxa'' Born, 1778: synonym of '' Chrysostoma paradoxum'' (Born, 1778)
* ''Helix perspicua'' Linnaeus, 1758: synonym of ''Lamellaria perspicua'' (Linnaeus, 1758)
* ''Helix petraea'' Montagu, 1803: synonym of '' Melarhaphe neritoides'' (Linnaeus, 1758)
* ''Helix platae'' Maton, 1811: synonym of ''Asolene platae'' (Maton, 1811)
* ''Helix priamus'' Gmelin, 1791: synonym of '' Ampulla priamus'' (Gmelin, 1791)
* ''Helix purpurea'' Gmelin, 1791: synonym of ''Cantharidus purpureus'' (Gmelin, 1791)
* ''Helix rodriguezensis'' Crosse, 1873: synonym of ''Dancea rodriguezensis'' (Crosse, 1873)
* ''Helix scabra'' Linnaeus, 1758: synonym of ''Littoraria scabra'' (Linnaeus, 1758)
* ''Helix scarabaeus'' Linnaeus, 1758: synonym of ''Pythia scarabaeus'' (Linnaeus, 1758)
* ''Helix serpuloides'' Montagu, 1808: synonym of ''Skenea serpuloides'' (Montagu, 1808)
* ''Helix solida'' Born, 1778: synonym of '' Phasianella solida'' (Born, 1778)
* ''Helix stagnalis'' Linnaeus, 1758: synonym of ''Lymnaea stagnalis'' (Linnaeus, 1758)
* ''Helix stagnorum'' Gmelin, 1791: synonym of ''Heleobia stagnorum'' (Gmelin, 1791): synonym of ''Semisalsa stagnorum'' (Gmelin, 1791)
* ''Helix subcarinata'' Montagu, 1803: synonym of '' Tornus subcarinatus'' ( Montagu, 1803)
* ''Helix subcylindrica'' Linnaeus, 1767: synonym of ''Truncatella subcylindrica'' (Linnaeus, 1767)
* ''Helix sulphurea'' C. B. Adams, 1849: synonym of '' Tonna pennata'' (Mörch, 1853)
* ''Helix tentaculata'' Linnaeus, 1758: synonym of ''Bithynia tentaculata'' (Linnaeus, 1758)
* ''Helix terebellum'' O. F. Müller, 1774: synonym of ''Pyramidella dolabrata'' (Linnaeus, 1758)
* ''Helix variabilis'' Megerle von Mühlfeld, 1824: synonym of ''Rissoa variabilis'' (Von Mühlfeldt, 1824)

Description

In addition to the hard, calcareous shell that covers and protects the internal organs, the head and foot regions can be observed when the snails are fully extended. When they are active, the organs such as the lung, heart, kidney, and intestines remain inside the shell; only the head and foot emerge.

The head of the snail has two pairs of tentacles; the upper and larger pair contains the eyes, and the lower pair is used to feel the ground in front. The mouth is located just underneath the head. The tentacles can be withdrawn or extended depending on the situation. The mouth has a tongue called a "radula" that is composed of many fine, chitinous teeth. This serves for rasping and cutting food.

Behaviour

From April through the northern summer, the number of snails copulating increases due to the higher temperature and humidity, which enhance the possibility of oviposition. The pulmonate snails are hermaphroditic, meaning that both female and male sexual organs are present in the same individual. The snails produce both eggs and sperm in the ovotestis (also called the hermaphrodite gland), but it is later separated into two divisions, a sperm duct and oviduct, respectively.

Mating takes several hours, sometimes a day. ''H. aspersa'' snails stab a calcite spine, known as a " love dart", at their partner. The love dart is coated with a mucus that contains a chemical that enables more than twice as many sperm to survive inside the recipient. A few days after mating, the eggs are laid in the soil. The eggs are usually 4–6 mm in diameter.

After snails hatch from the egg, they mature in one or more years, depending on where the organism lives. Maturity takes two years in Southern California, while it takes only 10 months in South Africa.

The size of the adult snails slightly varies with species. ''H. aspersa'' grows up to 35 mm in height and width, whereas ''H. pomatia'' grows up to 45 mm. The lifespan of snails in the wild is typically 2-3 years.

Some snails may live longer, perhaps even 30 years or older in the case of the Roman snail but most live less than 8 years. Many deaths are due to predators and parasites.

Since its publication in March 1974 issue of '' Natural History'' an estimate for the highest speed of garden snail equal to 0.03 mph (1.3 cm/s) became popular. However, the accuracy of this estimate has been questioned by Robert Cameron, who pointed out that in competitions between snails, only 2.4 mm/s speed had been achieved. There is a need for clarification and behavioural observation here though: competitions are usually held on the flat, whereas a snail's natural preference is vertical ascent, possibly an instinct derived from hatching in an earth "pod" and having to climb upwards to the surface.

Respiration

Since snails in the genus ''Helix'' are terrestrial rather than freshwater or marine, they have developed a simple lung for respiration. (Most other snails and gastropods have gills, instead.)

Oxygen is carried by the blood pigment hemocyanin. Both oxygen and carbon dioxide diffuse in and out of blood through the capillaries. A muscular valve regulates the process of opening and closing the entrance of the lung. When the valve opens, the air can either enter or leave the lung. The valve plays an important role in reducing water loss and preventing drowning.

Ecology

''Helix'' snails prefer cool, damp environments, as they easily suffer moisture loss. Snails are most active at night and after rainfall. During unfavourable conditions, a snail remains inside its shell, usually under rocks or other hiding places, to avoid being discovered by predators. In dry climates, snails naturally congregate near water sources, including artificial sources such as wastewater outlets of air conditioners.

The common garden snail (''H.aspersa'') is herbivorous. These snails are able to digest most vegetation, including carrots and lettuce. They also have a specialized crop of symbiotic bacteria that aid in their digestion, especially with the breakdown of the polysaccharide cellulose into simple sugars.

Many predators, both specialist and generalist, feed on snails. Some animals, such as the song thrush, break the shell of the snail by hammering it against a hard object, such as stone, to expose its edible insides. Other predators, such as some species of frogs, circumvent the need to break snail shells by simply swallowing the snail whole, shell and all.

Some carnivorous species of snails, such as the decollate snail and the rosy wolf snail, also prey on ''Helix'' snails. Such carnivorous snails are commercially grown and sold to combat pest snail species. Many of these also escape into the wild, where they prey on indigenous snails, such as the Cuban land snails of the genus ''Polymita'', and the indigenous snails of Hawaii.

Edible snails

''H. pomatia'' and ''H. aspersa'' are the two edible species that are most used in European cuisine. Spanish cuisine also uses '' Otala punctata'', ''Theba pisana'', and '' Iberus gualterianus alonensis'', amongst others. The process of snail farming is called heliciculture.

Escargots are often traditionally served as appetizers. They may also be used as ingredients in other recipes.

Snails contain many nutrients. They are rich in calcium and also contain vitamin B₁ and E. They contain various essential amino acids, and are low in calories and fat.

List of ''Helix'' species

There are also 6 extinct species of ''Helix'':
*'' Helix barbeyana'' De Stefani in De Stefani et al., 1891
*'' Helix divionensis'' J. Martin, 1866
*'' Helix krejcii'' Wenz in Krejci-Graf & Wenz, 1926
*'' Helix mrazeci'' Sevastos, 1922
*'' Helix sublutescens'' Wenz in Krejci & Wenz, 1926

Taxon inquirendum

* Helix (Cochlichondra) Jan, 1830
* Helix (Cochlogibba) Jan, 1830
* Helix (Patera) Albers, 1850 (Invalid: junior homonym of Patera Lesson, 1839 nidaria
* Helix achilli Bourguignat, 1883
* Helix acompsia (Bourguignat, 1863)
* Helix adelaidae L. Pfeiffer, 1857
* Helix adusta Hinds, 1845
* Helix ahmedi Pallary, 1899
* Helix aidae Pallary, 1899
* Helix alata L. Pfeiffer, 1856
* Helix albersi L. Pfeiffer, 1849
* Helix albidens Benson, 1853
* Helix alinae Pallary, 1899
* Helix alsiella Pallary, 1899
* Helix alveolus Heude, 1890
* Helix annamitica Crosse & Fischer, 1863
* Helix anomia Heude, 1890
* Helix ansorinus Theobald, 1866
* Helix appressa Say, 1821
* Helix arabophila Pallary, 1898
* Helix araneaetela Heude, 1885
* Helix artificiosa Benson, 1856
* Helix arundinetorum Heude, 1882
* Helix avidorum Cox, 1868
* Helix bahamensis L. Pfeiffer, 1845
* Helix barclayana L. Pfeiffer, 1847
* Helix barrakporensis Benson, 1859
* Helix batchianensis L. Pfeiffer, 1861
* Helix batesii L. Pfeiffer, 1860
* Helix beccarii Jickeli, 1874 (taxon inquirendum, replacement name for Helix ciliata non Venetz)
* Helix belcheri L. Pfeiffer, 1846
* Helix bicallosula Heude, 1886
* Helix biconvexa Martens, 1864
* Helix binneyana L. Pfeiffer, 1847
* Helix bizona Gredler, 1884
* Helix boissieri S. Moricand, 1846
* Helix bombax Benson, 1859
* Helix bonplandii Lamarck, 1822
* Helix bourguignati L. Pfeiffer, 1857
* Helix boxalli G. B. Sowerby III, 1888 (use in recent literature currently undocumented)
* Helix brocchii Jickeli, 1874 (invalid; not F. Sandberger, 1872)
* Helix brucei Jickeli, 1874 (use in recent literature currently undocumented)
* ''Helix bullina'' Férussac, 1832 (has also been mistakenly identified as ''Amphibulima rubescens'' Deshayes, 1830) Nathaniel F. Shoobs , Bram Breure, Revision-of-the-Lesser-Antillean-genera-Amphibulima-and-Pellicula
* Helix buvignieri Deshayes, 1874]
* Helix buxina Heude, 1886
* Helix caelatura Férussac, 1821
* Helix calpis Benson, 1859
* Helix calymma Schmacker & O. Boettger, 1894
* Helix campelica Mabille, 1886 (taxon inquirendum, no documented use in recent literature)
* Helix capessens Benson, 1856
* Helix carinata Link, 1807
* Helix carmeliensis L. Pfeiffer, 1861
* Helix carpalima J. Mabille, 1889
* Helix cassidula Benson, 1859
* Helix caucasica L. Pfeiffer, 1846
* Helix ceryx Benson, 1859
* Helix chadiana Pallary, 1899
* Helix cherifiana Pallary, 1899
* Helix chionodiscus L. Pfeiffer, 1857
* Helix cimex Reeve, 1854
* Helix coagulata L. Pfeiffer, 1856
* Helix conrauxiana Heude, 1885
* Helix conulus Martens, 1864
* Helix corneola Clessin, 1874
* Helix cumulus Reeve, 1854
* Helix cyclostomopsis I. Lea, 1834
* Helix cyclotrema Benson, 1863
* Helix cypsele L. Pfeiffer, 1849
* Helix cyrenaica E. von Martens, 1883
* ''Helix debauxii'' Noulet, 1854 †
* Helix decidua L. Pfeiffer, 1857
* Helix delavayana Heude, 1885
* Helix demolita Heude, 1885
* Helix depsta Cox, 1870
* Helix dhericourtiana Bourguignat, 1885
* Helix diaphana I. Lea, 1834
* Helix diniensis Rambur, 1868
* Helix doufourii Grateloup, 1840
* Helix dubia Clessin, 1874
* Helix ductilis Pfeiffer, 1857
* Helix egregia Deshayes, 1850
* Helix emmae Pallary, 1899
* Helix exacta L. Pfeiffer, 1863
* Helix exilis O. F. Müller, 1774
* Helix expansa Clessin, 1874
* Helix exserta L. Pfeiffer, 1856
* Helix faradensis L. Pfeiffer, 1861
* Helix fauna Philippi, 1851
* Helix faunus Broderip, 1841
* Helix ferretiana Bourguignat, 1883
* Helix filaris L. Pfeiffer, 1845
* Helix flammata Férussac, 1821
* Helix flaveola Martens, 1864
* Helix fornicata Gould, 1846
* Helix forrestiana Angas, 1875
* Helix fortunei Heude, 1882
* Helix fossaria Montagu, 1803
* Helix fritillata Benson, 1863
* Helix galinieriana Bourguignat, 1883
* Helix gaudiella Mabille, 1886 (taxon inquirendum, no documented use in recent literature)
* Helix gerlachi Möllendorff
* Helix gigas L. Pfeiffer, 1850
* Helix giraudeliana Heude, 1882
* Helix globula I. Lea, 1834
* Helix glomerosa Godwin-Austen, 1883
* Helix gordoniae Benson, 1863
* Helix graminum Heude, 1882
* Helix griffithi L. Pfeiffer, 1846
* Helix grossularia L. Pfeiffer, 1861
* Helix guadalcanarensis Cox, 1872
* Helix guinaria L. Pfeiffer, 1861
* Helix haesitans Heude, 1888
* Helix hamacenica Bourguignat, 1883
* Helix hamudae Kobelt, 1886 (taxon inquirendum, use in recent literature currently undocumented)
* Helix helmii G. B. Sowerby I, 1838 (taxon inquirendum, use in recent literature currently undocumented)
* Helix herbini Bourguignat, 1883
* Helix herpestes Heude, 1885
* Helix herza J. Mabille, 1889
* Helix hians L. Pfeiffer, 1846
* Helix hongkongensis Deshayes, 1874
* Helix horripilosella Heude, 1885
* Helix huberiana Heude, 1882
* Helix iae Pallary, 1899
* Helix improvisa Heude, 1885
* Helix ingloria Heude, 1890
* Helix involuta L. Pfeiffer, 1845
* Helix jacob Gredler, 1887
* Helix keratina Heude, 1889
* Helix kuangtunensis Gredler, 1881
* Helix labiata L. Pfeiffer, 1845
* Helix lamellata M. Bielz, 1851
* Helix languescens Heude, 1890
* Helix lariollei Pallary, 1899
* Helix latrunculorum Heude, 1885
* Helix lenticularis Morelet, 1853
* Helix linnaeana L. Pfeiffer, 1845
* Helix listeri Broderip, 1841
* Helix loxodon L. Pfeiffer, 1850
* Helix luctativa J. Mabille, 1889
* Helix lutuosa Deshayes, 1874
* Helix lyrata Gould, 1846
* Helix madritensis Rambur, 1868
* Helix mamilla
* Helix marcida Benson, 1853
* Helix margaritacea A. Schmidt, 1852
* Helix melillensis Pallary, 1899
* Helix mellita Heude, 1886
* Helix mellitula Heude, 1886
* Helix mendanae Cox, 1873
* Helix mendicaria L. Pfeiffer, 1860
* Helix mensalis Heude, 1888
* Helix meretrix G. B. Sowerby I, 1841 (taxon inquirendum, use in recent literature currently undocumented)
* Helix meridionalis Mousson, 1854 (taxon inquirendum, non Wood, 1828)
* Helix mersispira Martens, 1864
* Helix mesquiniana Pallary, 1898
* Helix micacea Heude, 1882
* Helix microzaffarina Pallary, 1898
* Helix mighelsiana L. Pfeiffer, 1847
* Helix miliaria Gredler, 1881
* Helix mimicula Heude, 1888
* Helix minutella J. Mabille, 1889
* Helix monodonta I. Lea, 1834
* Helix moquiniana Raymond, 1853
* Helix moretonensis Reeve, 1854
* Helix muscarum I. Lea, 1834
* Helix mystagoga J. Mabille, 1888
* Helix nautarum Heude, 1882
* Helix nicolai Klećak, 1880 (taxon inquirendum, use in more recent taxonomic literature currently undocumented)
* Helix novare L. Pfeiffer, 1861
* Helix nystiana L. Pfeiffer, 1846
* Helix oberndoerferi Kobelt, 1882 (taxon inquirendum, use in more recent taxonomic literature currently undocumented)
* Helix obscura Deshayes, 1874
* Helix oleosa L. Pfeiffer, 1850
* Helix omissa L. Pfeiffer, 1856
* Helix onisterella J. Mabille, 1889
* Helix opaca Gmelin, 1791
* Helix ophelia Reeve, 1854
* Helix ovumreguli I. Lea, 1834
* Helix pansa Benson, 1856
* Helix pantheia J. Mabille, 1888
* Helix papillata L. Pfeiffer, 1846
* Helix papillionacea Valenciennes, 1827
* Helix papyracea Broderip, 1841
* Helix paraeruginosa Heude, 1888
* Helix parasitarum Heude, 1885
* Helix parasitica Heude, 1885
* Helix paropta Mabille, 1886 (taxon inquirendum, no documented use in recent literature)
* Helix paulinae Pallary, 1899
* Helix peguensis Benson, 1860
* Helix pemphigodes L. Pfeiffer, 1847
* Helix pena Cox, 1868
* Helix penicillata Gould, 1842
* Helix pennantiana L. Pfeiffer, 1845
* Helix perforata Deshayes, 1874
* Helix permellita Heude, 1890
* Helix phragmitum Heude, 1882
* Helix phyllophaga Heude, 1882
* Helix pilidion Benson, 1860
* Helix pilifera E. von Martens, 1869
* Helix piligera Gredler, 1885
* Helix plicatilis Deshayes, 1870
* Helix pliculosa L. Pfeiffer, 1857
* Helix portoricensis L. Pfeiffer, 1847
* Helix praelongata Pallary, 1898
* Helix praeruginosa Heude, 1888
* Helix probata Mabille, 1898
* Helix prshewalskii Martens, 1881
* Helix prunum Férussac, 1821
* Helix puberosula Heude, 1885
* Helix purpuragula I. Lea, 1834
* Helix puteolus Benson, 1853
* Helix pyantha J. Mabille, 1889
* Helix pyramidalis G. B. Sowerby I, 1841 (taxon inquirendum, use in recent literature currently undocumented)
* Helix pyxis Hinds, 1845
* Helix quedenfeldti E. von Martens, 1890
* Helix quirosi Cox, 1873
* Helix radicicola Benson, 1859
* Helix radulella Heude, 1885
* Helix radulina Heude, 1888
* Helix rebellis Heude, 1885
* Helix reginae W. J. Broderip, 1841
* Helix renaltiana Heude, 1889
* Helix rerayana Pallary, 1899
* Helix rissoana L. Pfeiffer, 1847
* Helix rosacea G. B. Sowerby I, 1839 (taxon inquirendum, Invalid: junior homonym of Helix rosacea O. F. Müller, 1774)
* Helix rostrata L. Pfeiffer, 1847
* Helix rupelli Deshayes, 1870
* Helix samara Heude, 1886
* Helix samarella Heude, 1888
* Helix sanata Heude, 1889
* Helix sansitus Cox, 1870
* Helix saturnia Gould, 1846
* Helix savignyana Ehrenberg, 1831
* Helix saxatilis Gould, 1846 (taxon inquirendum, not Hartmann, 1821)
* Helix scenoma Benson, 1863
* Helix schweinfurthi E. von Martens, 1877
* Helix secundaria Heude, 1890
* Helix sedentaria Heude, 1885
* Helix seguiniana Heude, 1885
* Helix semicarinata Ancey, 1881
* Helix semifusca Deshayes, 1832
* Helix semigranosa G. B. Sowerby I, 1841 (taxon inquirendum, use in recent literature currently undocumented)
* Helix semirugosa Pallary, 1899
* Helix sempriniana Heude, 1882
* Helix sireti Pallary, 1898
* Helix sororia Cox, 1870
* Helix specialis Bourguignat, 1881
* Helix spengleriana L. Pfeiffer, 1847
* Helix spirillus Gould, 1852
* Helix squalus Hinds, 1845
* Helix squamosella Heude, 1882
* Helix squamulosa Mousson, 1856
* Helix stauropolitana A. Schmidt, 1855
* Helix strucki Maltzan, 1886 (taxon inquirendum, use in recent literature currently undocumented)
* Helix subcinctula Heude, 1890
* Helix subechinata Deshayes, 1870
* Helix subgranosa Le Guillou, 1842
* Helix subgriseola Heude, 1888
* Helix sublallementiana Pallary, 1899
* Helix subnivellina Bourguignat, 1883
* Helix subnuda J. Mabille, 1889
* Helix subparasitica Heude, 1888
* Helix suffulta Benson, 1853
* Helix sumatrana Martens, 1864
* Helix supracostata Kobelt, 1882 (taxon inquirendum, use in recent literature currently undocumented)
* Helix taliensis Heude, 1890
* Helix talifouensis Heude, 1888
* Helix tarifensis Bourguignat in Servain, 1881
* Helix tarnieri Pallary, 1899
* Helix tenuis L. Pfeiffer, 1845
* Helix terrestris Forskål, 1775
* Helix tescorum Benson, 1853
* Helix theobryta J. Mabille, 1889
* Helix thibetica Deshayes, 1870
* Helix tickelli Theobald, 1859
* Helix tristrami L. Pfeiffer, 1860
* Helix tumida L. Pfeiffer, 1846
* Helix turbinella Heude, 1890
* Helix tutuillae Cox, 1870
* Helix vannaelaeve Cox, 1870
* Helix variolosa L. Pfeiffer, 1846
* Helix vatheleti J. Mabille, 1888
* Helix vesica I. Lea, 1834
* Helix vesica L. Pfeiffer, 1842 (taxon inquirendum, not Helix vesica I. Lea, 1834)
* Helix vicinella Heude, 1890
* Helix vitiensis L. Pfeiffer, 1855
* Helix vitreola Heude, 1890
* Helix vivacula J. Mabille, 1889
* Helix vorticellina Heude, 1889
* Helix wanganensis Cox, 1870
* Helix welschi Pallary, 1899
* Helix woodiana I. Lea, 1834
* Helix yentaiensis Crosse & Debeaux
* Helix yorkensis Reeve, 1854
* Helix zelina Cox, 1873
* Helix zeus L. Pfeiffer, 1843
* Helix zollingeri L. Pfeiffer, 1854
* Helix zonites L. Pfeiffer, 1846
* Helix zorica J. Mabille, 1889
* Helix zoroaster Theobald, 1859

Nomen dubium

* Helix calomorpha Jonas, 1839
* Helix cornea Draparnaud, 1801
* Helix laevigata Linnaeus, 1767 accepted as Velutina laevigata (Linnaeus, 1767) (nomen dubium, original combination)
* Helix minutialis Deshayes, 1851
* Helix multispirata Hombron & Jacquinot, 1852
* Helix oceanica Le Guillou, 1842
* Helix rotula Hombron & Jacquinot, 1852 (nomen dubium, invalid: junior homonym of Helix rotula Lowe, 1831; no replacement name available)
* Helix rugosa L. Pfeiffer, 1843
* Helix undulata Gmelin, 1791
* Helix unispiralis Montagu, 1803

Nomen nudum

Subgenus Helix (Pitys) H. Beck, 1837
* Helix (Pitys) oparana H. Beck, 1837
* Helix angulata Férussac, 1821
* Helix congellana Krauss in E. von Martens, 1860
* Helix exoptata Tate, 1882
* Helix globula Krynicki, 1838
* Helix ingrami Blanford, 1876
* Helix roseri F. Krauss in E. von Martens, 1860
* Helix roseri Krauss in E. von Martens, 1860
* Helix somersetii Prime, 1853
* Helix tingitana Beck, 1837

References

{{DEFAULTSORT:Helix (Gastropod)

Helicidae
Gastropod genera
Extant Oligocene first appearances