Lineus is a genus of nemertine worms, including the bootlace worm, arguably the longest animal alive. Lineus contains the following species: * Southern, 1913 * Coe, 1934 * Verrill, 1900 * Verrill, 1900 * Takakura, 1898 * * Bürger, 1895 * * Korotkevich, 1978 * (Verrill, 1873) * Korotkevich, 1978 * (Schmarda, 1859) * (Grube, 1855) * (Bürger, 1890) * * Joubin, 1905 * Senz, 1996 * (Renier, 1804) * Gibson, 1990 * Sundberg & Gibson, 1995 * Takakura, 1898 * Moretto, 1971 * (Joubin, 1893) * Korotkevich, 1978 * Iwata, 1954 * Wheeler, 1940 * Takakura, 1898 * Punnett, 1903 * (Stimpson, 1855) * Bürger, 1892 * (Schmarda, 1859) * (Bürger, 1890) * Corrêa, 1958 * Punnett & Cooper, 1909 * Schmidt, 1946 * (Hubrecht, 1879) * Senz, 1997