SYNOPSISSpecimens ofAskenasia volvoxfrom southwestern Indiana have a variable body shape and a size range of 29 × 22μm to 42 × 27μm. The pectinelles, membranelles, and cirri each number 47–48, and respectively have a length of 8–10, 20, and 30μm. The pectinelles arise from ciliary rows consisting of ∼10 kinetosomes, and every membranelle originates from 2 adjacent rows of ∼14–17 kinetosomes. Different algae as well asBodoand certain other protozoa are ingested. The macronucleus, micronucleus, the cytoplasm and its inclusions, trichites, the function of the contractile vacuole, and movements and behavior