Annelida Lamarck, 1809 - segmented worms
   "polychaetes" see Class Polychaeta Grube, 1850
     Palpata G.W. Rouse & K. Fauchald, 1997
       Aciculata G.W. Rouse & K. Fauchald, 1997
         Phyllodocida see Order Phyllodocida Dales, 1962
           Nereidiformia see Suborder Nereidiformia
             Family Hesionidae Grube, 1850
               Genus [Sirsoe] Pleijel, 1998
                 Sirsoe methanicola (D. Desbruyères & A. Toulmond, 1998) - methane ice worm