The Collaborative International Dictionary of English v.0.48:

Catallacta \Cat`al*lac"ta\, n. pl. [NL., fr. Gr. ?. See
   Catallactics.] (Zool.)
   A division of Protozoa, of which Magosph[ae]ra is the type.
   They exist both in a myxopod state, with branched
   pseudopodia, and in the form of ciliated bodies united in
   free, spherical colonies.
   [1913 Webster]