The Collaborative International Dictionary of English v.0.48:

Devilfish \Dev"il*fish`\, n. (Zool.)
   (a) A huge ray (Manta birostris or Cephaloptera vampyrus)
       of the Gulf of Mexico and Southern Atlantic coasts.
       Several other related species take the same name. See
       Cephaloptera.
   (b) A large cephalopod, especially the very large species of
       Octopus and Architeuthis. See Octopus.
   (c) The gray whale of the Pacific coast. See Gray whale.
   (d) The goosefish or angler (Lophius), and other allied
       fishes. See Angler.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Cephaloptera \Ceph`a*lop"te*ra\
   (s[e^]f`[.a]*l[o^]p"t[-e]*r[.a]), n. [NL., fr. Gr. kefalh`
   head + ptero`n wing.] (Zool.)
   One of the generic names of the gigantic ray (Manta
   birostris) of the family Mobulidae, known as devilfish,
   sea devil, manta and manta ray. It is common on the
   coasts of South Carolina, Florida, and farther south, and is
   sometimes found as far north as New York Bay. Some of them
   grow to enormous size, becoming twenty feet of more across
   the body, and weighing more than a ton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Manta birostris
    n 1: largest manta (to 22 feet across wings); found worldwide
         but common in Gulf of Mexico and along southern coasts of
         United States; primarily oceanic [syn: Atlantic manta,
         Manta birostris]