An outline for the reclassification of the Chytridiales, and for a new order, the Spizellomycetales

An outline is presented for the reclassification of the Chytridiales into two orders based on fundamental differences in zoospore ultrastructure. The new order Spizellomycetales includes species with the Phlyctochytrium–Entophlyctis type of zoospore and also Karlingia, Olpidium, and Rozella. Four new genera, Spizellomyces, Gaertneriomyces, Triparticalcar, and Kochiomyces replace the Phlyctochytrium complex. The revised Chytridiales includes species with the Rhizophydium–Chytridium–Nowakowskiella type of zoospore, as well as Synchytrium,