New host record for the entodiniomorphid ciliate, Troglodytella abrassarti, from siamangs (Hylobates syndactylus).

Examination of faecal samples from several diarrhoeic siamangs Hylobates syndactylus (Anthropoidea: Hylobatidae) revealed the presence of numerous entodiniomorphid ciliates whose morphological and ultrastructural characteristics were consistent with those of Troglodytella abrassarti previously recorded from chimpanzees, orangutans and gorillas (Anthropoidea: Pongidae).