Examination of scrapings from the gingival space at the base of the teeth of 50 coolies in the District Hospital, Kuala Lumpur, Federated Malay States, revealed the presence of the following parasitic protozoa: Entamoeba gingivalis (Gros, 1849) Brumpt, 1913, and a species of Trichomonas. Most of the coolies were patients in the malaria wards, and in no case was the patient in hospital for any kind of mouth affection. Since a fair body of evidence has already accumulated against the pathogenicity of E. gingivalis, and none for it, no special consideration was given to this point (Goodrich and Moseley, 1916). A very cursory review of the dental condition of these patients produced nothing in conflict with such evidence. Some of these coolies keep their mouths very clean: most of them cleanse their teeth daily, but they use no disinfectant. The Indians make use of charcoal and the Chinese of powdered cuttle-bone. The habit of chewing sirih, very prevalent among the Indians, seems to be without effect on the mouth protozoa. Both species were found in mouths deeply stained with the betel juice, and on one occasion together with a wad of the chewing mixture.