The Collaborative International Dictionary of English v.0.48:

Infusory \In*fu"so*ry\, a. (Zool.)
   Infusorial.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Infusory \In*fu"so*ry\, n.; pl. Infusories. (Zool.)
   One of the Infusoria; -- usually in the pl.
   [1913 Webster]