leucosoidn.

/ˈl(j)uːkəsɔɪd/Etymology: < modern Latin Leucosia ( < Greek λευκός white) the name of the typical genus + -oid suffix.
Zoology.
1852 J. D. Dana 48 But in the Leucosoids, there is a higher perfecting of the branchial system.
This entry has not yet been fully updated (first published 1902; most recently modified version published online June 2018).