SUMMARYSyncephalis sphaerica(PiptocephaUdaceae, Mucorales) is a biotrophic, haustorial mycoparasite. Fifty genera of fungi, representing four classes, were tested as potential hosts for the parasite. Twenty genera of Mucorales supported growth and sporulation ofS. sphaerica.A single ascomycete (a yeast) and two members of the Deuteromycetes were also parasitized byS. sphaerica.None of the Basidiomycetes tested supported growth of the parasite.Axenic culture ofS. sphaericawas partially successful, with dense mycelial growth and some sporulation on certain media. The use of certain filtrates with host exudates as well as the use of killed mycelium to support growth was unsuccessful. The host range and axenic culture ofS. sphaericaare compared toS. californicaand species ofPiptocephalis.