The Collaborative International Dictionary of English v.0.48:

Lepidosiren \Lep`i*do*si"ren\ (-s[imac]"r[e^]n), n. [Gr. lepi`s
   -i`dos, a scale + seirh`n a siren.] (Zool.)
   An eel-shaped ganoid fish of the order Dipnoi, having both
   gills and lungs. It inhabits the rivers of South America. The
   name is also applied to a related African species
   (Protopterus annectens). The lepidosirens grow to a length
   of from four to six feet. Called also doko.
   [1913 Webster] Lepidote

The Collaborative International Dictionary of English v.0.48:

Doko \Do"ko\, n. (Zool.)
   See Lepidosiren.
   [1913 Webster]