Leptothyra is a genus of sea snails, marine gastropod mollusks in the family Colloniidae.
This genus was previously placed in the family Turbinidae.
The name Leptothyra is generally attributed to Pease (1869), and the name "Leptothyra Pease, 1869" is usually treated as a valid name for small colloniines. Although Leptothyra is a junior objective synonym of Homalopoma, the species usually treated as valid in that genus are provisionally listed in WoRMS under "Leptothyra sensu Pease, 1869", pending a taxonomic/nomenclatural reappraisal.
Leptothyra J. G. Cooper, 1867 is now considered a synonym of the genus Homalopoma Carpenter, 1864
The small, solid shell has a turbinate or globose shape. The operculum is multispiral with a subcentral nucleus and concave in the centre outside. The main character distinguishing Collonia from Leptothyra seems to be the peculiar peristome of the former.
Species within the genus Leptothyra include:
Leptothyra balnearii Pilsbry, H.A., 1920
Leptothyra benthicola (Marshall, 1979)
Leptothyra candida Pease, 1861
Leptothyra filifer (Deshayes, 1863)
Leptothyra grossa Feng, 1996
Leptothyra inepta (Gould, A.A., 1861)
Leptothyra kermadecensis (Marshall, 1979)
Leptothyra morini Viader, R., 1951
Leptothyra nanina (Souverbie in Souverbie & Montrouzier, 1864)
Leptothyra rubens Melvill & Standen, 1903
Leptothyra rubricincta (Mighels, 1845)
Leptothyra verruca (Gould, 1845)
Species brought into synonymy
Leptothyra africana Bartsch, 1915: synonym of Cinysca spuria (Gould, 1861)
Leptothyra agulhasensis Thiele, 1925: synonym of Homalopoma agulhasense (Thiele, 1925)
Leptothyra albida Dall, 1881: synonym of Homalopoma albidum (Dall, 1881)
Leptothyra albocincta Turton, 1932: synonym of Tricolia striolata (Turton, 1932)
Leptothyra alfredensis Bartsch, 1915: synonym of Parviturbo alfredensis (Bartsch, 1915)
Leptothyra arenacea Pritchard & Gatliff, 1902: synonym of Charisma arenacea (Pritchard & Gatliff, 1902)
Leptothyra carminea Bartsch, 1915: synonym of Homalopoma quantillum carmineum (Bartsch, 1915)
Leptothyra coelata A. Adams, 1854: synonym of Anadema macandrewii Mörch, 1868
Leptothyra costata Pease, 1869: synonym of Leptothyra verruca (Gould, 1845)
Leptothyra crassilirata Preston, 1909: synonym of Collonista crassilirata (Preston, 1909)
Leptothyra cunninghami E. A. Smith, 1881: synonym of Homalopoma cunninghami (E. A. Smith, 1881)
Leptothyra delecta E. A. Smith, 1899: synonym of Collonista delecta (E. A. Smith, 1899)
Leptothyra eroopolitana (Issel, 1869) : synonym of Turbo eroopolitanus Issel, 1869
Leptothyra eucosmia Turton, 1932: synonym of Cinysca spuria (Gould, 1861)
Leptothyra fluctuata (Hutton, 1883): synonym of Argalista fluctuata (Hutton, 1883)
Leptothyra gestroi Caramagna, 1888: synonym of Yaronia gestroi (Caramagna, 1888)
Leptothyra globuloides Dautzenberg & H. Fischer, 1896: synonym of Cantrainea globuloides (Dautzenberg & H. Fischer, 1896)
Leptothyra induta Watson, 1879: synonym of Homalopoma indutum (Watson, 1879)
Leptothyra induta var. tincta Dall, 1889: synonym of Homalopoma indutum (Watson, 1879)
Leptothyra induta var. insculpta Dall, 1889: synonym of Homalopoma indutum (Watson, 1879)
Leptothyra innocens Thiele, 1912: synonym of Leptocollonia innocens (Thiele, 1912)
Leptothyra insculpta Dall, 1889: synonym of Homalopoma indutum (Watson, 1879)
Leptothyra laeta (Montrouzier in Souverbie & Montrouzier, 1863): synonym of Collonia granulosa Pease, 1868
Leptothyra limata Dall, 1889: synonym of Homalopoma linnei (Dall, 1889)
Leptothyra linnei Dall, 1889: synonym of Homalopoma linnei (Dall, 1889)
Leptothyra paucicostata Dall, 1871: synonym of Homalopoma paucicostatum (Dall, 1871)
Leptothyra philipiana Dall, 1889: synonym of Cantrainea philipiana (Dall, 1889)
Leptothyra picta Marshall, 1979: synonym of Leptothyra kermadecensis Marshall, 1979
Leptothyra quantilla (Gould, 1861): synonym of Homalopoma quantillum (Gould, 1861)
Leptothyra rotundata (G.B. Sowerby III, 1892): synonym of Homalopoma rotundatum (G.B. Sowerby III, 1892)
Leptothyra sakaensis Yokoyama, 1925: synonym of Littorina brevicula (Philippi, 1844)
Leptothyra sanguinea Linnaeus, 1758: synonym of Homalopoma sanguineum (Linnaeus, 1758)
Leptothyra solida Preston, 1908: synonym of Collonista solida (Preston, 1908)
Leptothyra tincta Dall, 1889: synonym of Homalopoma indutum (Watson, 1879)
