Pellicles of the ciliate Tetrahymena pyriformis strain GL (phenoset A) were isolated by a new procedure. Oral apparatuses also purified by a modification of a pervious method. Both preparations were characterized by electron microsocpy. Proteins of the isolates were separated by analytical SDD polyacrylamide gel electrophoresis. The isolated pellicles, which included oral apparatuses, contained only 6 major proteins (gel bands), designated A through F. Bands A, B, and C, were found in the pellicle fraction, but not in the oral apparatus fraction. Therefore, these proteins are believed to be present in the somatic cortex of Tetrahymena. Bands D and E were greatly enriched in the oral apparatus fraction; these proteins are therefore believed to be present primarily in the oral apparatus. Band F, identified as tubulin, was present in both preparations. Molecular weight determinations and some selective solubilization experiments are also presented.