78 (77) Buccal cilia in apical counterclockwise groups that descend 

 helically down a deep, tubular buccal cavity. Animal cup- or 

 bell-shaped, solitary or colonial 79 



78 (77) Buccal cilia inconspicuous, in groups within apical cone or funnel. 



Animal cylindrical or spindle-shaped, with flaring apex, noncolonial 81 



79 (78) A differentiated stalk present. 



80 



79 (78) Stalk absent. Family SCYPHIDIIDAE. 



80 (79) Stalk contractile. Family VORTICELLIDAE. 



80 (79) Stalk not contractile. Family EPISTYLIDIDAE. 



30 



