YEASTLIKE dematiaceous fungi from various sources are occasionally isolated in all microbiologic laboratories, and organisms of that type have been described in the literature from time to time under such names as Saccharomyces niger, Schizosaccharomyces niger, Torula nigra, Monilia nigra and Pullularia pullulans. They are generally known as "black yeasts." Our knowledge of this mycologic group in regard to morphology, relationships and pathogenic habits is still incomplete, and the fungi in question are generally considered as contaminating agents having no relation whatsoever with pathologic changes observed in human beings. However, recent observations would tend to confirm that certain species in that group are capable of producing disease. It is the purpose of this communication (1) to review briefly two dermatoses, namely, tinea nigra and chromoblastomycosis, in which fungi of the "black yeast" type have been found to be etiologically important, (2) to present a study of two species