1911 Encyclopædia Britannica/Aspirotrichaceae

ASPIROTRICHACEAE (O. Bütschli), an order of Ciliate Infusoria, characterized by an investment, general or partial, of nearly uniform cilia, without any distinct adoral wreath, and one or two adoral endoral undulating membranes. With the Gymnostomaceae it formed the Holotricha of Stein.