Abstract
Three hitherto undescribed mold coloring matters, iridoskyrin, rubroskyrin and erythroskyrine, were isolated from strains of P. islandicum. The relationships of iridoskyrin and rubroskyrin to other mold coloring matters are discussed. Erythroskyrine is a highly unsaturated, light-labile substance which shows some anti-bacterial activity against Staphylococcus species. The distribution of 7 crystalline coloring matters in 10 strains of P. islandicum has been investigated and is described.