Mysis \My"sis\, n. [NL., fr. Gr. ? a closing of the lips or eyes.]

(Zo["o]l.) A genus of small schizopod shrimps found both in fresh and salt water; the opossum shrimps. One species inhabits the Great Lakes of North America, and is largely eaten by the whitefish. The marine species form part of the food of right whales.

Source: Webster's Revised Unabridged Dictionary (1913)