Several samples of asphaltic marls from the Island of Buton have been analysed on diatoms. These samples after their treatment with solvents to eliminate the asphalt content appeared to consist of greyish or yellowish white marls. Despite the vigorous treatment with several solvents, by which the asphalt content was reduced to a small fraction of a percent, it proved to be impossible to prepare and wash the samples in the usual way. Only after heating them to about 800° F. for several hours, they could with much care be washed and cleaned adequately for final examination. The samples were labelled: Waisioe and Kaboengka.