Dichotomous key to Collothecidae

1 Anterior end of adults a small to large, cup- or funnel-shaped structure (infundibulum), corona absent; infundibulum with 0–7 extensions (apices, knobs, lobes, tentacles), elongate setae usually present (sometimes with cilia) around the margin; trophi uncinate................................................................. Order Collothecacea Harring, 1913 [All species are solitary; both sessile and planktonic species are known; juveniles (larvae) possess a ciliated corona used in locomotion, but this is lost at metamorphosis and replaced by the infundibulum.]

1’ Anterior end of adults with a corona with typical ciliated lobes or fields, or ciliated bands; trophi malleoramate................................................................................. Order Flosculariaceae Harring, 1913 [Species may be solitary or colonial; both sessile and planktonic species are known; juveniles (larvae) possess a corona that is retained (and grows) during ontogeny.]