A TAXONOMIC REAPPRAISAL OF THE GENUS CERIOSPOROPSIS BASED ON ULTRASTRUCTURE

This paper reports results of ultrastructural studies of ascospores an d their appendages in Ceriosporopsis caduca, Ceriosporopsis circumvest ita, and Ceriosporopsis capillacea. Ceriosporopsis caduca and C. capil lacea have polar appendages that arise as outgrowths of the spore wall . The exosporium, which initially extends over the polar appendages, l ater forms a collar at their base. In C. circumvestita, the sheath is mesosporial in origin and is chambered; an exosporium is absent, and t here is no collar at the base of the appendage. Because of the differe nce in ascospore appendage structure, C. circumvestita is transferred to a new genus Lautisporopsis. The taxonomy of the remaining species o f Ceriosporopsis is reviewed, and comparisons are made with Bovicornua intricata.