ianthina \ian"thina\, n.; pl. l. ianthinae, e.
   ianthinas. nl., fr. l. ianthinus violet-blue, gr. ?; ?
   violet + ? flower. zool.
   any gastropod of the genus ianthina, of which various
   species are found living in mid ocean; -- called also purple
   shell, and violet snail. written also janthina.
   1913 webster

   note: it floats at the surface by means of a raft, which it
         constructs by forming and uniting together air bubbles
         of hardened mucus. the tyrian purple of the ancients
         was obtained in part from mollusks of this genus.
         1913 webster
see also:
ianthinae ianthinas ianthina purple shell violet snail janthina 

janthina \jan"thina\, n. zool.
   see ianthina.
   1913 webster
see also:
ianthina