As nouns the difference between protozoan and folliculinid

is that protozoan is (cytology) any of the diverse group of eukaryotes, of the phylum protozoa, that are primarily unicellular, existing singly or aggregating into colonies, are usually nonphotosynthetic, and are often classified further into phyla according to their capacity for and means of motility, as by pseudopods, flagella, or cilia while folliculinid is (biology) any marine, ciliate protozoan of the family .

As an adjective protozoan

is of, pertaining to, or characteristic of a protozoan.