| Nominal Species (n = 113) | Present allocation (n = 109) | Ref. |
|---|---|---|
| Ophiodissa alternata Fraser, 1938 | Ophiodissa alternata | 19 |
| Halecium amphibolum Watson, 1993 | Halecium amphibolum | 8278 |
| Halecium annulatum Torrey, 1902 | Halecium annulatum | 19 |
| Halecium antarcticum Vanhöffen, 1910 | Halecium antarcticum | 8278 |
| Ophiodissa arborea Allman, 1888 | Hydrodendron arboreum | 3477 |
| Halecium arboreum Allman, 1888 | Hydrodendron arboreum | 87630 |
| Halecium arcticum Ronowicz & Schuchert, 2007 | Halecium arcticum | 3477 |
| Halecium articulosum Clark, 1875 | Halecium articulosum | 19 |
| Halecium banyulense Motz-Kossowska, 1911 | Halecium banyulense | 8278 |
| Halecium bermudense Congdon, 1907 | Halecium bermudense | 19 |
| Halecium birulai Spassky, 1929 | Halecium birulai | 8278 |
| Halecium brashnikowi Linko, 1911 | Halecium brashnikowi | 8278 |
| Halecium bruniensis Watson, 1975 | Halecium bruniensis | 8278 |
| Mitrocomium cirratum Haeckel, 1879 | Mitrocomium cirratum | 3477 |
| Halecium conicum Stechow, 1919 | Halecium conicum | 8278 |
| Halecium corrugatissimum Trebilcock, 1928 | Halecium corrugatissimum | 19 |
| Halecium corrugatum Nutting, 1899 | Halecium corrugatum | 19 |
| Halecium crinis Stechow, 1913 | Halecium crinis | 8278 |
| Halecium curvicaule von Lorenz, 1886 | Halecium curvicaule | 19 |
| Halecium cymiforme Allman, 1888 | Halecium cymiforme | 8278 |
| Halecium cymosum Fraser, 1935 | Halecium cymosum | 8278 |
| Halecium delicatulum Coughtrey, 1876 | Halecium delicatulum | 19 |
| Halecium densum Calkins, 1899 | Halecium densum | 19 |
| Halecium dichotomum Allman, 1888 | Halecium dichotomum | 813 |
| Halecium diminutivum Fraser, 1940 | Halecium diminutivum | 19 |
| Halecium dubium Fraser, 1941 | Halecium dubium | 8278 |
| Halecium dyssymetrum Billard, 1929 | Halecium dyssymetrum | 3477 |
| Halecium dysymmetrum Billard, 1929 | Halecium dysymmetrum | 19 |
| Halecium exiguum Fraser, 1938 | Halecium exiguum | 19 |
| Halecium expansum Trebilcock, 1928 | Halecium expansum | 19 |
| Halecium fasciculatum Fraser, 1938 | Halecium fasciculatum | 19 |
| Halecium filicula Allman, 1877 | Halecium filicula | 8278 |
| Halecium fjordlandicum Galea, 2007 | Halecium fjordlandicum | 3477 |
| Halecium flabellatum Fraser, 1935 | Halecium flabellatum | 8278 |
| Halecium flexile Allman, 1888 | Halecium delicatulum | 19 |
| Halecium flexum Fraser, 1938 | Halecium flexum | 19 |
| Halecium fragile Hodgson, 1950 | Halecium fragile | 19 |
| Halecium fraseri Ralph, 1958 | Halecium fraseri | 8278 |
| Halecium fruticosum Fraser, 1943 | Halecium fruticosum | 19 |
| Halecium galeatum Billard, 1937 | Halecium galeatum | 8278 |
| Halecium gracile Verrill, 1874 | Halecium halecinum | 19 |
| Halecium groenlandicum Kramp, 1911 | Halecium groenlandicum | 19 |
| Halecium humile Pictet, 1893 | Halecium humile | 8278 |
| Halecium incertus Naumov & Stepan'yants, 1962 | Halecium incertus | 3125 |
| Halecium inhacae Millard, 1958 | Halecium inhacae | 8278 |
| Halecium insolens Fraser, 1938 | Halecium insolens | 19 |
| Hemitheca intermedia Hilgendorf, 1898 | Hemitheca intermedia | 19 |
| Halecium interpolatum Ritchie, 1907 | Halecium interpolatum | 8278 |
| Halecium jaederholmi Vervoort, 1972 | Halecium jaederholmi | 8278 |
| Halecium kofoidi Torrey, 1902 | Halecium kofoidi | 19 |
| Halecium kuekenthali Marktanner-Turneretscher, 1890 | Halecium curvicaule | 75097 |
| Halecium labiatum Billard, 1933 | Halecium labiatum | 8278 |
| Halecium labrosum Alder, 1859 | Halecium labrosum | 19 |
| Halecium laeve Kramp, 1932 | Halecium laeve | 8278 |
| Ophiodissa laxa Fraser, 1938 | Ophiodissa laxa | 19 |
| Halecium lenticulare Trebilcock, 1928 | Halecium lenticulare | 19 |
| Halecium lightbourni Calder, 1991 | Halecium lightbourni | 813 |
| Halecium linkoi Antsulevich, 1980 | Halecium linkoi | 8278 |
| Halecium liouvillei Billard, 1934 | Halecium liouvillei | 8278 |
| Halecium lucium Antsulevich, 1979 | Halecium lucium | 8278 |
| Halecium luteum Watson, 1975 | Halecium luteum | 8278 |
| Halecium macrocephalum Allman, 1877 | Halecium macrocephalum | 19 |
| Halecium marsupiale Bergh, 1887 | Halecium marsupiale | 19 |
| Campalecium medusiferum Torrey, 1902 | Campalecium medusiferum | 19 |
| Mitrocomium medusiferum Torrey, 1902 | Mitrocomium medusiferum | 19 |
| Halecium minor Fraser, 1935 | Halecium minor | 8278 |
| Halecium minutum Broch, 1903 | Halecium minutum | 19 |
| Halecium mirandus Antsulevich & Regel, 1986 | Halecium mirandus | 8278 |
| Halecium mutilum Allman, 1876 | Halecium mutilum | 87751 |
| Halecium nanum Alder, 1859 | Halecium nanum | 19 |
| Halecium obovatum Watson, 2018 | Halecium obovatum | 3477 |
| Halecium ochotense Linko, 1911 | Halecium ochotense | 19 |
| Halecium ornatum Nutting, 1901 | Halecium ornatum | 19 |
| Halecium ovatum Totton, 1930 | Halecium ovatum | 8278 |
| Halecium pallens Jäderholm, 1904 | Halecium pallens | 3477 |
| Halecium parvulum Bale, 1888 | Halecium delicatulum | 19 |
| Endothecium paucinodum Fraser, 1947 | Endothecium paucinodum | 19 |
| Halecium perexiguum Hirohito, 1995 | Halecium perexiguum | 8278 |
| Halecium petrosum Stechow, 1919 | Halecium petrosum | 8278 |
| Halecium plicatocarpum Vervoort & Watson, 2003 | Halecium plicatocarpum | 8278 |
| Halecium plumosum Hincks, 1868 | Halecium plumosum | 19 |
| Halecium profundum Calder & Vervoort, 1998 | Halecium profundum | 8278 |
| Halecium pusillum Sars, 1850 | Halecium pusillum | 19 |
| Halecium pygmaeum Fraser, 1911 | Halecium pygmaeum | 19 |
| Halecium pyriforme Hirohito, 1995 | Halecium pyriforme | 8278 |
| Halecium ralpha Watson & Vervoort, 2001 | Halecium ralpha | 3477 |
| Endothecium reduplicatum Fraser, 1935 | Endothecium reduplicatum | 19 |
| Halecium reflexum Stechow, 1919 | Halecium reflexum | 19 |
| Halecium regulare Fraser, 1938 | Halecium regulare | 19 |
| Halecium repens Jäderholm, 1907 | Halecium repens | 8278 |
| Halecium reversum Nutting, 1901 | Halecium reversum | 19 |
| Halecium robustum Nutting, 1901 | Halecium robustum | 19 |
| Halecium schneideri Bonnevie, 1898 | Halecium schneideri | 8278 |
| Halecium scutum Clark, 1877 | Halecium scutum | 8278 |
| Halecium secundum Jäderholm, 1904 | Halecium secundum | 8278 |
| Halecium sessile Norman, 1867 | Halecium sessile | 8278 |
| Halecium sibogae Billard, 1929 | Halecium sibogae | 8278 |
| Halecium spatulum Watson, 2000 | Halecium spatulum | 8278 |
| Halecium speciosum Nutting, 1901 | Halecium speciosum | 19 |
| Hydrodendron sympodiformis Millard & Bouillon, 1974 | Hydrodendron sympodiformis | 8278 |
| Halecium telescopicum Allman, 1888 | Halecium telescopicum | 19 |
| Halecium tenellum Hincks, 1861 | Halecium tenellum | 19 |
| Halecium tensum Fraser, 1941 | Halecium tensum | 8278 |
| Halecium tenue Fraser, 1938 | Halecium tenue | 19 |
| Halecium textum Kramp, 1911 | Halecium textum | 8278 |
| Halecium tortum Fraser, 1938 | Halecium tortum | 8278 |
| Hydrodendron tottoni Rees & Vervoort, 1987 | Hydrodendron tottoni | 19 |
| Halecium undulatum Billard, 1921 | Halecium undulatum | 1663 |
| Halecium vagans Fraser, 1938 | Halecium vagans | 19 |
| Halecium vasiforme Fraser, 1935 | Halecium vasiforme | 8278 |
| Hydrodendron violaceum Hirohito, 1995 | Hydrodendron violaceum | 8278 |
| Halecium washingtoni Nutting, 1899 | Halecium washingtoni | 19 |
| Halecium wilsoni Calkins, 1899 | Halecium wilsoni | 19 |