- Omalaxis exquisita Dall & C. T. Simpson, 1901 accepted as Omalaxis exquisitus Dall & C. T. Simpson, 1901 accepted as Spirolaxis centrifuga (Monterosato, 1890)
- Omalaxis exquisitus Dall & C. T. Simpson, 1901 accepted as Spirolaxis centrifuga (Monterosato, 1890)
- Omalaxis nobilis A. E. Verrill, 1885 accepted as Pseudomalaxis zanclaeus (R. A. Philippi, 1844)
- Omalaxis sarsi K. J. Bush, 1897 accepted as Orbitestella sarsi (K. J. Bush, 1897)
- Omalaxis supranitida (S. V. Wood, 1848) sensu G. O. Sars, 1878 accepted as Orbitestella sarsi (K. J. Bush, 1897)