n. In Lamarck's classification (1801–12), one of three orders of Annelida, distinguished from Apoda and Antennata, and containing the sedentary or tubicolous worms: opposed to Errantia.n. 2. The sedentary spiders: same as Sedentariæ.n. 3. A suborder of peritrichous ciliate infusorians, containing those which are sedentary, as the Vorticellidæ: distinguished from Natantia.