It is difficult to overestimate the importance of the mould genera Penicillium and Aspergillus in the natural world and in the affairs of man. These are large and ub1quitous genera; several species are beneficial to mankind because of their role in food fermentation or the production of useful antibiotics and enzymes. Others are important as agents of food spoilage. In recent years, these moulds have ga1ned attention because a number of species produce toxic metabo­ lites. The great impact of mycotoxicology on food problems, particularly in developing countries has generated a vast body of research. The ecological roles of Aspergillus and Penicil­ lium species in nature is also of importance. For the past several decades, the taxonomic treatments of Raper and Thorn (1949) and Raper and Fennell (1965)