With plural agreement. A former major grouping of the animal kingdom including invertebrates with no distinct nervous system.
In the terminology of W. W. Macleay, Acrita was established as a fifth subkingdom alongside the four of Cuvier. In the terminology of R. Owen, Acrita was conceived as a loose group or series of the Radiata and later considered equivalent to the Protozoa.
Early 19th century; earliest use found in Annals of Philosophy. From scientific Latin Acrita from ancient Greek ἄκριτος undistinguishable, undecided, doubtful, not giving judgement (from ἀ- + κριτός chosen) + scientific Latin -a.