32 



PROTOCOCCALES 



2. Chlamydospores verrucose 



B. Chlamydospores forming a 



beneath the epidermis 



continuous layer 



Protomycopsis F 306 

 Taphridium 18:203, F 306 



Family 3. CHYTRIDIACEAE 



Fitzpatrick 88, 100; Minden 209 



Mycelium present, consisting typically of short delicate more or less branched 

 hyphae, endoph\tic or epiphytic; sporangia single and terminal or several and inter- 

 calary, often with a sterile swollen cell at base; resting spores similar; zoospores 

 1-ciliate. 



The limits of genera are even more indefinite in this family than in the order 

 as a whole. This arises partly from the great difficulty of investigating adequately 

 forms of such transitory nature and relatively infrequent occurrence. It seems 

 probable that it is caused even more by an exceptional degree of plasticity, in nature 

 but also especially in culture, arising from the hypertrophy due to an intense para- 

 sitism. These difficulties have been appreciated by Fitzpatrick in particular and his 

 treatment has been adopted in the following key, except for a few minor details. 



Subfamily Chytridiae 



Mycelium usually confined to one or two cell 



single sporangium 



A. Mycelium wholly intramatrical 

 1. Sporangia epibiotic 

 a. Mycelium consisting of delicate more or less 

 branching threads 



(1) Resting spores intramatrical; on Pan- 



dorina 



(2) Resting spores epibiotic or lacking 



(a) Mycelium usually monophagous; resting 

 spore producing zoospores 

 X. Sporangia with a basal vesicle 

 (x) Sporangia with extramatrical stalk 

 m. Sporangia with a solid apical spine, 

 in open connection with stalk; 

 saprophytes 

 n. Sporangia without apical spine, a 

 septum between it and the stalk; 

 in Pinnularia 

 (y) Sporangia without extramatrical 



stalk 

 m. Orifice apical 

 (m) Sporangia opening by a lid; in 



Cylindrocystis 

 (n) Sporangia without a lid 

 r. Sporangia emitting a vesicle in 

 which the zoospores are 

 formed 

 s. Sporangia with internal forma- 

 tion of zoospores 

 (r) Zoospores escaping normally; 

 typically algicole 



s of the host, bearing a 



Dangeardia 96 



Obelidium 92 



Podochytrium 92 



Zygorhizidium 93 



Rhizidiomyces 93 



Phlyctochytrium 94; 1 



