Dichotomous key to order Collothecacea
1 Infundibulum bearing setae and/or cilia; with or without lobes (tentacles, knobs, or apices); gelatinous tubes; sessile or planktonic...................................................................... Collothecidae Bartoš, 1959
1’ Infundibulum lacking cilia or setae; unlobed or with one long, very flexible lobe, or with short, horny processes; with or without gelatinous tube; sessile or benthic (crawling)............................................ Atrochidae Bartoš, 1959