Crustacea (n.)

arthropod class, 1814, Modern Latin neuter plural of crustaceus (animalia), literally "having a crust or shell," from Latin crusta "crust, rind, bark, hard shell" (from PIE root *kreus- "to begin to freeze, form a crust;" also see -a (2)). Taken as a zoological classification by Lamarck, 1801; Cuvier (1798) had les insectes crustacées.