In our first communication concerning the pigments of Penicillium islandicum Sopp (Howard & Raistrick 1949) it was shown that the dried mycelium of laboratory cultures of one strain of this species, no. N.R.R.L. 1036, contained about 20% of its weight of a complex mixture of colouring matters. One constituent of this mixture was isolated and identified as the hitherto undescribed islandicin (1:4:5 trihydroxy-2-methylanthraquinone, I). This substance was isolated from the mycelium of five out of six morphologically typical strains of P. islandicum, and the presence in the mycelium of several other colouring matters was indicated by a number of colour reactions. Three of these colouring matters have now been isolated in a pure crystalline state and it is the purpose of the present communication to describe, inter alia, their isolation, properties and reactions, and to discuss their relationship to other fungal colouring matters. None of them appears to have been described previously. Their chemical constitutions, at present uncertain, are under investigation in this laboratory.