1. Amoeba occasionally feeds on the ciliate Frontonia.
2. In the instances of feeding observed, the Frontonia was not ingested whole but was cut in half by the Amoeba.
3. One half of the Frontonia is engulfed in a food cup of the Amoeba, the pseudopods of the cup producing an annular constriction in the middle region of the ciliate.
4. The pseudopodial collar or cup flows distally and presses against the free half of the Frontonia. Thus the halves are pushed continuously farther apart, until the attenuated interconnecting strand is severed and one-half of the Frontonia is simultaneously engulfed.
The writer is indebted to Professor S. O. Mast for many valuable suggestions in connection with this work.