An 18 year old female athlete, who recently competed in a barefoot run for charity in Southern Georgia, presented to her doctor for a routine check-up. Other than complaining of being exhausted and having occasional diarrhea, she was in good health. The doctor ordered a stool for culture and parasite examination. The culture was negative. Numerous suspicious forms, as that shown here, were seen upon microscopic examination of the stool. The name of this suspicious form is:

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