1. In discoid fungi the Ascus may be operculate, opening with a lid or similar discharge mechanism, and relatively thin-walled, or it may be inoperculate and thick-walled.

2. Zygorhizidium affluens Canter and Z. planktonicum Canter have monocentric operculate sporangia and zoospores which have single lipid globules to which the cell nucleus and single mitochondrion are closely adpressed.