Supplement VI provides an index to the family, generic, infrageneric and specific names of ferns and fern allies published between 1976 and 1990. It is a continuation of Carl Christensen s Index Filicum (1906), the three supplements prepared by Christensen (1913, 1917 and 1934), the fourth by Pichi Sermolli (1965) and the fifth by Jarrett (1985). I