Source : Webster's Revised Unabridged Dictionary (1913)

Hyperotreta \Hy`per*o*tre"ta\, n. pl. [NL., fr. Gr. ? the plate
   + ? perforated.] (Zo["o]l.)
   An order of marsipobranchs, including the Myxine or hagfish
   and the genus {Bdellostoma}. They have barbels around the
   mouth, one tooth on the plate, and a communication between
   the nasal aperture and the throat. See {Hagfish}. [Written
   also {Hyperotreti}.]

Source : WordNet®

Hyperotreta
     n : hagfishes as distinguished from lampreys [syn: {Myxiniformes},
          {suborder Myxiniformes}, {suborder Hyperotreta}, {Myxinoidei},
          {Myxinoidea}, {suborder Myxinoidei}]