Emarginula

Emarginula is a genus of small keyhole limpets, marine gastropod molluscs in the family Fissurellidae.

Description
The oval shell is obliquely conical with a backward-pointing recurved apex. There is a deep incision in the anterior margin. A distinct anal fasciole extends upwards from this incision. The surface is latticed, sculptured with radial ribs. There is no septum inside.

Radula
The radula has a dental formula of [many].1.4.1.4.1.[many], with a wide, rectangular, acuspate rachidian tooth. The various genera have a few dozen rows of teeth.

Species
According to the World Register of Marine Species (WoRMS), species within the genus Emarginula include:


 * Emarginula adamsiana Sowerby in Adams & Sowerby, 1863
 * Emarginula adriatica Costa O.G., 1829
 * Emarginula agulhasensis Thiele, 1925
 * Emarginula alba Watson, 1897
 * Emarginula amyda Shikama, 1962
 * Emarginula angusta McLean, 1970
 * Emarginula annielangleitae Poppe & Tagaro, 2020
 * Emarginula apolonia Pacaud, 2015
 * Emarginula balicasagensis Poppe & Tagaro, 2020
 * Emarginula bicancellata Montrouzier, 1860
 * Emarginula bonfittoi Smriglio & Mariottini, 2001
 * Emarginula boucheti Poppe & Tagaro, 2020
 * Emarginula camilla Melvill & Standen, 1903
 * Emarginula candida Adams, 1852
 * Emarginula choristes Dall, 1925
 * Emarginula christiaensi Piani, 1985
 * Emarginula circumalbum P oppe & Tagaro, 2020
 * Emarginula clypeus Adams, 1852
 * Emarginula colipanoae Poppe & Tagaro, 2020
 * Emarginula compta Habe, 1953
 * Emarginula concinna Adams, 1852
 * Emarginula connectens Thiele, 1915
 * Emarginula connelli Kilburn, 1978
 * Emarginula convexa Hedley, 1907
 * Emarginula costulata Deshayes, 1863
 * Emarginula crassa Sowerby, 1812
 * Emarginula crassicostata Sowerby in Adams & Sowerby, 1863
 * Emarginula curvamen Iredale, 1925
 *  Emarginula cuvieri Audouin, 1827 (species inquirenda)
 *  Emarginula decorata Deshayes, 1863
 * Emarginula delonguevilleae Poppe & Tagaro, 2020
 * Emarginula devota Thiele, 1915
 * Emarginula dictya McLean, 1970
 * Emarginula dilecta Adams, 1852
 * Emarginula divae (van Aartsen & Carrozza, 1995)
 * Emarginula dubia Schepman, 1908
 * † Emarginula espibosensis Lozouet, 1999
 * † Emarginula fenestrata Deshayes, 1861 †
 * Emarginula fenestrella Deshayes, 1863
 * Emarginula fissura (Linnaeus, 1758) - slit limpet
 * † Emarginula fossorensis Lozouet, 1999
 * Emarginula foveolata Schepman, 1908
 * Emarginula foveolata fugitai Habe, 1953
 * Emarginula fragilis Yokoyama, 1920
 * Emarginula fulginea Adams, 1851
 * Emarginula gabensis (Gabriel, 1961)
 * † Emarginula galeriformis Marwick, 1928
 * † Emarginula gigantea Poppe, 2008
 * Emarginula gustavi Poppe & Tagaro, 2020
 * Emarginula hataii Habe, 1953
 * Emarginula hawaiiensis Dall, 1895
 * † Emarginula haweraensis Powell, 1931
 * Emarginula hosoyai Habe, 1953
 * Emarginula huzardii (Payraudeau, 1826)
 * Emarginula icosisculpta Simone & Cunha, 2014
 * Emarginula imaizumi Dall, 1926
 * † Emarginula imbricata Millet, 1865
 * Emarginula imella Dall, 1926
 * Emarginula intervecta Locard, 1898 : synonym of Emarginula fissura (Linnaeus, 1758)
 * Emarginula janae Cossignani, 2020
 * Emarginula japonica Sowerby in Adams & Sowerby, 1863
 * Emarginula jungcheni K.-Y. Lai, 2019
 * † Emarginula kaiparica Laws, 1939
 * Emarginula kashimaensis Shikama, 1962
 * † Emarginula komitica Laws, 1939
 * Emarginula koon Kilburn, 1978
 * Emarginula lata J.R.C. Quoy & J.P. Gaimard, 1834
 * Emarginula liuzzii Poppe & Tagaro, 2020
 * Emarginula longifissa Sowerby, 1866
 * Emarginula lorenzoi Giusti & Micali, 2019
 * Emarginula macclurgi Kilburn, 1978
 * Emarginula mactanensis Poppe & Tagaro, 2020
 * Emarginula maculata Adams in Adams & Sowerby, 1863
 * Emarginula margarita Poppe & Tagaro, 2020
 * Emarginula micans Adams, 1852
 * Emarginula multistriata Jeffreys, 1882
 * Emarginula natalensis Barnard, 1963
 * Emarginula nigromaculata (Thiele, 1930)
 * Emarginula nordica Pérez Farfante, 1947 - northern emarginula
 * † Emarginula oblonga Sandberger, 1859
 * Emarginula obovata Adams, 1852
 * Emarginula octaviana Coen, 1939
 * Emarginula oppressa Barnard, 1963
 * Emarginula paivana (Crosse, 1867)
 * Emarginula patula Cotton, 1930
 * † Emarginula paucicostata Laws, 1936
 * Emarginula paucipunctata Schepman, 1908
 * Emarginula philippinensis Poppe & Tagaro, 2020
 * Emarginula phrixodes Dall, 1927 - ruffled emarginula
 * Emarginula pittensis Marwick, 1928
 * Emarginula poppeorum Romani & Crocetta, 2017
 * † Emarginula praesicula Lozouet, 1999
 * Emarginula puncticulata Adams, 1852
 * Emarginula punctulum Piani, 1980
 * Emarginula pustula Thiele in Küster, 1913
 * Emarginula quadrata Poppe & Tagaro, 2020
 * Emarginula regia Habe, 1953
 * Emarginula retecosa Adams, 1851
 * Emarginula rosea Bell, 1824
 * Emarginula scabriuscula Adams, 1852
 * Emarginula sicula Gray, 1825 - dagger emarginula
 * Emarginula sinica Lu, 1986
 * Emarginula solidula Costa, 1829
 * Emarginula souverbiana Pilsbry, 1890
 *  Emarginula spinosa Deshayes, 1863
 * Emarginula striatula Quoy and Gaimard, 1834 - dagger emarginula
 * Emarginula subtilitexta Verco, 1908
 * Emarginula superba Hedley, 1906
 * Emarginula suspira Simone & Cunha, 2014
 * Emarginula tenera Locard, 1892
 * † Emarginula teneraeformis Lozouet, 1999
 * Emarginula tenuicostata Sowerby, 1863
 * Emarginula teramachii Habe, 1953
 * Emarginula textilis Gould, 1859 in 1859-61
 * Emarginula thomasi Crosse, 1864
 * Emarginula thorektes Kilburn, 1978
 * Emarginula tosaensis Habe, 1953
 * Emarginula tuberculosa Libassi, 1859 - tuberculate emarginula
 * Emarginula undulata Melvill & Standen, 1903
 * Emarginula velascoensis Shasky, 1961
 * Emarginula velascoi Rehder, 1980
 * Emarginula viridibrunneis Poppe & Tagaro, 2020
 * Emarginula viridicana Herbert & Kilburn, 1985
 * Emarginula viridis Poppe & Tagaro, 2020
 * Emarginula xishaensis Lu, 1986
 * Emarginula yangeorum Poppe & Tagaro, 2020

The following species are mentioned in other databases : The Indo-Pacific Molluscan Database also mentions the following species with names in current use :
 * Emarginula curvata Schepman, 1908
 * Emarginula multisquamosa Schepman, 1908
 * Emarginula sublaevis Schepman, 1908


 * Subgenus Emarginula Lamarck, 1801
 * Emarginula bellula Adams, 1851
 * Emarginula cucullata Adams, 1851
 * Emarginula fissurata Adams, 1851
 * Emarginula harmilensis Sturany, 1903
 * Emarginula plana Schepman, 1908
 * Emarginula scabricostata Adams, 1851
 * Subgenus Emarginula (Subzeidora) Iredale, 1924


 * Species brought into synonymy:


 * Emarginula altilis Gould, 1859: synonym of Variemarginula punctata (A. Adams, 1852)
 * Emarginula amitina Iredale, 1925: synonym of Emarginula dilecta A. Adams, 1852
 * Emarginula angustata Thiele, 1915: synonym of Tugali decussata A. Adams, 1852
 * Emarginula arabica A. Adams, 1852: synonym of Octomarginula arabica (A. Adams, 1852)
 * Emarginula arconatii Issel, 1869: synonym of Montfortista panhi (Quoy & Gaimard, 1834)
 * Emarginula australis Quoy & Gaimard, 1834: synonym of Montfortia subemarginata (Blainville, 1819)
 * Emarginula bella Gabb, 1865: synonym of Scelidotoma bella (Gabb, 1865)
 * Emarginula biangulata Sowerby, 1901: synonym of Emarginella biangulata (G. B. Sowerby III, 1901)
 * † Emarginula blainvillii Defrance, 1825 : synonym of  † Rimula blainvillii (Defrance, 1825)
 * Emarginula brevirimata Deshayes, 1862: synonym of Montfortula brevirimata (Deshayes, 1862)
 * Emarginula clathrata A. Adams & Reeve, 1850: synonym of Montfortista panhi (Quoy & Gaimard, 1834)
 * Emarginula clathrata Pease, 1863: synonym of Emarginula dilecta A. Adams, 1852
 * Emarginula conica Lamarck, 1801: synonym of Emarginula fissura (Linnaeus, 1758)
 * Emarginula conica Schumacher, 1817 non Lamarck, 1801: synonym of Emarginula rosea Bell, 1824
 * Emarginula dentigera Heilprin, 1889: synonym of Hemimarginula dentigera (Heilprin, 1889)
 * Emarginula elata Locard, 1898 : synonym of Emarginula christiaensi Piani, 1985
 * Emarginula elongata O. G. Costa, 1829: synonym of Emarginula octaviana Coen, 1939
 * Emarginula eximia A. Adams, 1852 : synonym of Emarginella eximia (A. Adams, 1852)
 * Emarginula flindersi Cotton, 1930: synonym of Emarginula convexa Hedley, 1907
 * Emarginula fuliginea Kuroda, 1941: synonym of Variemarginula variegata (A. Adams, 1852)
 * Emarginula guernei Dautzenberg & Fischer, 1896: synonym of Emarginula tuberculosa Libassi, 1859
 * Emarginula hedleyi Thiele, 1915: synonym of Emarginula candida A. Adams, 1852
 * Emarginula incisula(sic): synonym of Emarginella incisura (A. Adams, 1852)
 * Emarginula incisura A. Adams, 1852 : synonym of Emarginella incisura (A. Adams, 1852)
 * Emarginula kimberti Cotton, 1930: synonym of Laeviemarginula kimberti (Cotton, 1930)
 * Emarginula modesta H. Adams, 1872: synonym of Hemimarginula modesta (H. Adams, 1872)
 * Emarginula muelleri Forbes & Hanley, 1849: synonym of Emarginula fissura (Linnaeus, 1758)
 * Emarginula ostheimerae Abbott, 1958: synonym of Octomarginula ostheimerae (Abbott, 1958)
 * Emarginula panhi Quoy & Gaimard, 1834: synonym of Montfortista panhi (Quoy & Gaimard, 1834)
 * Emarginula papillosa Risso 1826 : synonym of Emarginula huzardii Payraudeau, 1826
 * Emarginula parmophoidea Quoy & Gaimard, 1834: synonym of Tugali elegans Gray, 1843
 * Emarginula peasei Thiele, 1915: synonym of Emarginula dilecta A. Adams, 1852
 * Emarginula phrygium Herbert & Kilburn, 1985 : synonym of Agariste phrygium (Herbert & Kilburn, 1986) (original combination)
 * Emarginula picta Dunker, 1860: synonym of Montfortula picta (Dunker, 1860)
 * Emarginula pileata Gould, 1859: synonym of Variemarginula punctata (A. Adams, 1852)
 * Emarginula pileum Heilprin, 1889: synonym of Hemimarginula pileum (Heilprin, 1889)
 * Emarginula planulata A. Adams, 1852 : synonym of Emarginella planulata (A. Adams, 1852)
 * Emarginula polygonalis A. Adams, 1852: synonym of Hemitoma polygonalis (A. Adams, 1852)
 * Emarginula pulchreclathrata Tomlin, 1932: synonym of Emarginula agulhasensis Thiele, 1925
 * Emarginula pumila A. Adams, 1852: synonym of Hemimarginula pumila (A. Adams, 1852)
 * Emarginula punctata A. Adams, 1852: synonym of Variemarginula punctata (A. Adams, 1852)
 * Emarginula reticulata Sowerby, 1813: synonym of Emarginula fissura (Linnaeus, 1758)
 * Emarginula rugosa Quoy & Gaimard, 1834: synonym of Montfortula rugosa (Quoy & Gaimard, 1834)
 * Emarginula scutellata Deshayes, 1863: synonym of Octomarginula scutellata (Deshayes, 1863)
 * Emarginula sibogae Schepman, 1908: synonym of Emarginella sibogae (Schepman, 1908)
 * Emarginula simpla Christiaens, 1987: synonym of Hemimarginula simpla (Christiaens, 1987)
 * Emarginula stellata A. Adams, 1852: synonym of Montfortula rugosa (Quoy & Gaimard, 1834)
 * Emarginula subclathrata Pilsbry, 1890: synonym of Emarginula dilecta A. Adams, 1852
 * Emarginula subemarginata Blainville, 1819: synonym of Montfortia subemarginata (Blainville, 1819)
 * Emarginula subrugosa Thiele, 1916: synonym of Hemimarginula subrugosa (Thiele, 1916)
 * Emarginula sulcifera A. Adams, 1852: synonym of Montfortulana sulcifera (A. Adams, 1852)
 * Emarginula tricarinata Pilsbry, 1890: synonym of Montfortista panhi (Quoy & Gaimard, 1834)
 * Emarginula tricostata G.B. Sowerby I, 1823: synonym of Hemitoma octoradiata (Gmelin, 1791)
 * Emarginula vadososinuata Yokoyama, 1922: synonym of Tugalina vadososinuata (Yokoyama, 1922)
 * Emarginula vadum Barnard, 1963: synonym of Emarginula undulata Melvill & Standen, 1903
 * Emarginula variegata A. Adams, 1852: synonym of Variemarginula variegata (A. Adams, 1852)