A vast majority of the tens of thousands of marine and non-marine gastropod species are normally dextral (right handed - i. e., the shell opening is to the right when held spire upwards) while only a limited number of taxa such as Busycon perversum, the few species of the fasciolariid subgenus Sinistralia, and most of the speciose families Triphoridae and Clausiliidae, are normally sinistral (left handed - the shell opening visible on the left when held spire upwards). However, accidents of nature do happen, and occasionally a sinistral specimen of a normally dextral species or a dextral specimen of a normally sinistral species will be found - albeit rarely to uniquely. It is likely that most such reversals are caused by a single gene mutation.

     In some 48 years of specializing in "reverse coiled" or "abnormally sinistral or dextral" gastropods, Jacksonville amateur malacologist Harry G. Lee has assembled a collection of 175 individual species, eleven collected by himself, which had coiled in a direction contrary to the norm. This collection includes 106 Recent, four fossil marine and 65 non-marine species. A listing of the species is presented below by family in phylogenetic order; genus and species are thereinunder alphabetical. Shell measurement is presented in cm. followed by collection location and the year collected. A year listed in parentheses is the year a specimen was acquired when the actual year of collection was not known. A "+" following the listed entry indicates that more than one specimen is present in the collection.

The thirty-year peregrination of the exquisite sinistral Ancillista velesiana Iredale, 1936: a chronology

Faux Sinistral Cymatium pileare (Linnaeus, 1758) From The Philippines

Faux Sinistral Conus From The Philippines

Faux Sinistral Cymatium pyrum (Linnaeus, 1758)

Which Way Does A Sundial turn?

• Turbinidae Turbo sarmaticus Linnaeus, 1758 2.85 Algoa Bay, South Africa. 2001.
• Neritidae Nerita striata Burrow, 1815 2.40 Philippines. (2006).
• Triviidae Trivia ovulata (Lamarck, 1810) 1.62 Jeffreys Bay, South Africa. 2002.
• Triviidae Trivia phalacra (F. Schilder, 1930) 1.65 Jeffreys Bay, South Africa. (1990).
• Cypraeidae Cypraeovula alfredensis (M. Schilder and F. A. Schilder, 1929) 2.60 Jeffreys Bay, South Africa. 2005.
• Cypraeidae Cypraeovula capensis (Gray, 1825) 3.11 Algoa Bay, South Africa, 2008.
• Cypraeidae Cypraeovula edentula (Gray,1825) 2.37 Jeffreys Bay, South Africa. 1996.
• Cypraeidae Cypraeovula fuscodentata (Gray, 1825) 2.93 Jeffreys Bay, South Africa. 1995.
• Cypraeidae Notocypraea angustata (Gmelin, 1791) 2.66 Port MacDonnell, South Australia. 1977.
• Naticidae Polinices flemingianus (Récluz, 1844) 1.87 Mactan, P.I. (1975).
• Muricidae Calotrophon ostrearum (Conrad, 1864) 2.32 Pine Is., FL. 1978.
• Muricidae Chicoreus damicornis (Hedley, 1903) 2.61 Cape Moreton, Australia. 1968.
• Muricidae Chicoreus margaritensis (Abbott, 1958) 8.21 Isla Margarita, Venezuela. 1999.
• Muricidae Haustellum haustellum (Linnaeus, 1758) 7.46 Tuticorin, India 1999.
• Muricidae Hexaplex cichoreum (Gmelin, 1791) 5.67 Sulu, P.I. (1975). +
• Muricidae Murex falsitribulus Ponder and E. Vokes, 1988 5.44 India. (1985).
• Muricidae Vokesimurex bellegladeensis (E. Vokes, 1963) 3.58 Canaveral, FL. 1983.
• Buccinidae Afrocominella capensis (Dunker in Philippi, 1844) 1.33 Jeffreys Bay, South Africa. (2002).
• Buccinidae Buccinum undatum Linnaeus, 1758 6.52 England. (1984).
• Buccinidae Hesperisternia multangulus (Philippi, 1848) 2.00 Clearwater, FL. 1962.
• Buccinidae Neptunea constricta (Dall, 1907) 13.97 Off South Korea. 2006.
• Buccinidae Neptunea cumingii Crosse, 1862 6.00 Yellow Sea off China (38.5052N 121.4142E). (2005).
• Buccinidae Pseudoneptunea varicosa (Gmelin, 1791) 2.74 Gulf of Siam, Thailand (2007). 
• Columbellidae Euplica scripta (Lamarck, 1822) 1.20 Coron Is., Palawan, Philippines (1999).
• Melongenidae Brunneifusus ternatanus (Gmelin, 1791) 9.36 Bohol, P.I. 2001. +
• Melongenidae Busycon carica (Gmelin, 1791) 9.53 Fernandina, FL. 1983.
• Melongenidae Busycon perversum (Linnaeus, 1758) 24.13 Sanibel, FL. 1979. (species is normally sinistral)
• Melongenidae Busycotypus canaliculatus (Linnaeus, 1758) 14.48 Cape Cod, MA. 1984.
• Melongenidae Melongena bispinosa (Philippi, 1844) 3.12 Isla Mujeres, Mexico. (2001).
• Melongenidae Melongena corona (Gmelin, 1791) 4.19 Marco Is., FL. 1979.
• Melongenidae Volegalea cochlidium (Linnaeus, 1758) 8.3 India. (1970).
• Melongenidae Volema myristica (Röding, 1798) 4.33 Cebu, P.I. (1975).
• Nassariidae Bullia melanoides (Deshayes, 1832) 2.42 Rameswaran, India. (1983).
• Fasciolariidae Cinctura hunteria (G. Perry, 1811) 5.03 Madeira Beach, FL. 1991.
• Fasciolariidae Peristernia castanoleuca Tapparone-Canefri, 1879 2.40 Balabac, PI (2004).
• Fasciolariidae Peristernia fuscotincta (G. B. Sowerby III, 1886) 1.30 Mzamba, South Africa.  1989.
• Fasciolariidae Sinistralia gallagheri Smythe and Chatfield, 1981 2.03 Al Masirah Is., Oman. 1984. (species is normally sinistral)
• Olividae Agaronia gibbosa (Born, 1778) 3.80 off Kalikarai, India. (2003).
• Olividae Ancilla albozonata E. A. Smith, 1904 1.75 Jeffreys Bay, South Africa. (1987).
• Olividae Ancilla ampla ampla (Gmelin, 1791) 1.73 Madras, India. 1987.
• Olividae Ancilla cinnamomea Lamarck, 1801 2.40 Madras, India. 1980. +
• Olividae Eburna lienardi (Bernardi, 1858) 4.51 Recife, Brazil. 1996. W/Xray
• Olividae Olivancillaria vesica vesica (Gmelin, 1791) 4.35 Arraial do Cabo, Brazil. 2000.
• Olividae Olivella pusilla (Marrat, 1871) 0.88 Port St. Joe, FL. 1983.
• Turbinellidae Tudivasum armigerum (A. Adams, 1855) 6.18 Keppel Bay, Australia. 1969.
• Turbinellidae Turbinella pyrum (Linné, 1767) 10.35 Southeast India. (1986).
• Turbinellidae Turbinella regina Heilprin, 1886 16.21 APAC Pit, Sarasota, FL. 1983. (extinct fossil species)
• Turbinellidae Vasum turbinellus (Linnaeus, 1758) 5.78 Mactan, P.I. (1975).
• Volutidae Amoria undulata (Lamarck, 1804) 7.35 Botany Bay, Australia. 1979.
• Volutidae Cymbiola complexa (Iredale, 1924) 7.87 Colundra, Australia. 1962.
• Volutidae Cymbiola nobilis (Lightfoot, 1786) 12.56 Nha Trang, Vietnam. 2005.
• Volutidae Cymbiola vespertilio (Linnaeus, 1758) (Linnaeus, 1758) 6.11 Sulu, P.I. 1969. +
• Volutidae Cymbium cucumis (Röding, 1798) 16.24 Accra, Ghana. 1966.
• Volutidae Melo aethiopica (Linnaeus, 1758) 8.95 Indonesia 2012.
• Volutidae Melo melo (Lightfoot, 1786) 15.28 Viet Nam. (2004).
• Cystiscidae Gibberula lavalleeana (d'Orbigny, 1842) 0.24 Pinellas Co., FL. 2000.
• Cystiscidae Granulina hadria (Dall, 1889) 0.23 Little Torch Key, FL. 1978.
• Cystiscidae Granulina species D of Redfern, 2013 [Redfern, 2013: 176, 577, (3) figs. no. 501] 0.19 Pinecrest beds, Sarasota Co. FL. 2015.
• Cystiscidae Pugnus serrei (Bavay, 1911) 0.10 Marathon, FL. 1986.
• Marginellidae Bullata bullata (Born, 1778) 4.58 Itaparica, Brazil. 1969.
• Marginellidae Bullata lilacina (G. B. Sowerby II, 1846) 2.05 Fortaleza, Brazil. 2017.
• Marginellidae Closia giadae Cossignani, 2001 2.55 Majenga, Malagasy Rep. 2000.
• Marginellidae Cryptospira angustata (G. B. Sowerby II, 1846) 1.69 Madras, India. (1981).
• Marginellidae Cryptospira elegans (Gmelin, 1791) 2.42 Ranong, Thailand. 1985.
• Marginellidae Cryptospira tricincta (Hinds, 1844) 2.45 Taiwan. 1986.
• Marginellidae Cryptospira ventricosa (G. Fischer, 1807) 2.58 Lombok, Indonesia. 2016. + Also see: Cryptospira ventricosa Sinistral
• Marginellidae Dentimargo aureocinctus (Stearns, 1872) 0.33 Anclote, FL. 1976.
• Marginellidae Dentimargo reductus (Bavay, 1922) 0.33 Isla Cubagua, Venezuela. 2005.
• Marginellidae Glabella ansonae Clover, 1973 2.07 Nacala Bay, Mozambique. 2006.
• Marginellidae Hyalina lucida (Marrat, 1877) 0.73 Port Elizabeth, South Africa. 1994.
• Marginellidae Marginella albocincta (G. B. Sowerby I, 1846) 1.67 Jeffreys Bay, South Africa. (2013).
• Marginellidae Marginella aurantia Lamarck, 1822 2.20 Dakar, Senegal. 1995.
• Marginellidae Marginella bairstowi G. B. Sowerby III, 1886 1.70 Jeffreys Bay, South Africa. (2006).
• Marginellidae Marginella floccata G. B. Sowerby II, 1889 2.52 Eastern Cape, South Africa. (2000).
• Marginellidae Marginella lineolata G. B. Sowerby III, 1886 2.53 Jeffreys Bay, South Africa. 1993.
• Marginellidae Marginella lutea G. B. Sowerby II, 1889 1.96 Jeffreys Bay, South Africa. (1985).
• Marginellidae Marginella mosaica G. B. Sowerby II, 1846 3.54 Jeffreys Bay, South Africa. August, 1996.
• Marginellidae Marginella ornata Redfield, 1870 2.92 Jeffreys Bay, South Africa. 1995.
• Marginellidae Marginella piperata Hinds, 1844 1.62 Jeffreys Bay, South Africa. (2000).
• Marginellidae Marginella sebastiani Marche-Marchad and Rosso, 1979 4.51 Senegal (2002).
• Marginellidae Mesoginella turbinata (G. B. Sowerby II, 1846) 0.83 Angelsea, Victoria, Australia. 1991.
• Marginellidae Protoginella fraudulenta (Suter, 1917) 0.33 Otago, New Zealand. 1989. (extinct fossil species)
• Marginellidae Prunum apicinum (Menke, 1828) 1.15 Long Is., Bahamas. 1977.
• Marginellidae Prunum capense (Krauss, 1848) 1.16 Buffels Bay, South Africa. (1986).
• Marginellidae Prunum curtum (G. B. Sowerby I, 1832) 1.79 Pisco, Ica, Peru. 1993.
• Marginellidae Prunum guttatum (Dillwyn, 1817) 1.56 Ambergris Key, Belize. 1984.
• Marginellidae Prunum keenii (Marrat, 1871) 1.32 Eastern Cape, South Africa. (2000).
• Marginellidae Prunum labiatum (Kiener, 1841) 2.81 Yucatan, E. Mexico. (1978).
• Marginellidae Prunum pellucidum (L. Pfeiffer, 1850) 0.82 West Indies. (1989).
• Marginellidae Prunum pruinosum (Hinds, 1844) 1.38 Belize, Belize. 1980.
• Marginellidae Prunum succinea (Conrad, 1866) 1.10 Bradenton, FL. 1973.
• Marginellidae Volvarina avena (Kiener, 1834) 0.88 Marathon, FL. 1977.
• Marginellidae Volvarina effulgens (Reeve, 1865) 1.06 Coney Is., Bermuda. 1980.
• Marginellidae Volvarina hirasei (Bavay, 1917) 6.3 Zamboanga, Philippines. 2004.
• Marginellidae Volvarina obscura (Reeve, 1865)  1.26 Muscat, Oman. 1978.
• Marginellidae Volvarina philippinarum (Redfield, 1848) 1.43 Santa Rosa Is., P.I. 1979. +
• Marginellidae Volvarina warrenii (Marrat, 1876) 1.44 Off Mar del Plata, Argentina. 2008.
• Marginellidae Volvarina sp. B [Redfern, 2001: no. 453] 0.45 Cat Is., Bahamas. 2008.
• Mitridae Isara picta (Reeve, 1844) 3.02 Beach, Cape St. Francis, South Africa. (2001).
• Mitridae Quasimitra latruncularia (Reeve, 1844) 2.39  Jeffreys Bay, South Africa. 2001.
• Conidae Conus anabathrum Crosse, 1865 3.14 Marco Is., FL. 1967.
• Conidae Conus baccatus G. B. Sowerby II, 1877 2.01 Coiba Is., (Pacific) Panama. (1991).
• Conidae Conus furvus Reeve, 1843 3.11 Midanao, P.I. (1975).
• Conidae Conus infrenatus Reeve, 1848 3.26 Jeffreys Bay, South Africa. 1997.
• Conidae Conus tinianus Hwass in Bruguière, 1792  2.81 Jeffreys Bay, South Africa. 1994.
• Conidae Conus ventricosus Gmelin, 1791 1.33 La Maddalena Is., Sardinia. 1972. +
• Terebridae Neoterebra dislocata (Say, 1822) 2.79 Borrow pit, Hastings, FL. 1996. (sinistral specimen is a fossil of this extant species from the Upper Pliocene of the Nashua Formation, ca. 3 MYA)
• Turridae Asthenotoma lamothei (Dautzenberg, 1910) 0.90 Dakhla, Western Sahara. (1991).
• Turridae Clionella borni (E. A. Smith, 1877) 2.75 Jeffreys Bay, South Africa. 2002.
• Architectonicidae Heliacus variegatus (Gmelin, 1791) 1.3, 1.4 Negros (L), Siasi Sulu (R), Philippines. (2005).