protozoa

pl. [PROTOZOON.] Zool .: A group of animals, occupying the lowest sponggos =a sponge.] 1. Zool .: [PROT EROS PONG I A.] 2. Palæont.: A genus of Keratoda (?), with four species, from the Lower Silurian. "The minute structure of this old type is very imperfectly known." ( Nicholson .) Protospongia fenestrata is from the Lower Cam brian. ( Hicks .)