CHYTRIDIALES 239 



fines of Cohrfs concept of the species. The resting-spore stage is that 

 described by Serbinow. No forms were included which did not fall 

 within these limits. Mere records, as well as globose types which were 

 imperfectly observed, were excluded. The following were considered 

 inadmissible: 



1. Schenk (1858a: 237), on Oedogonium sp. (1858b: 8), on Oscilla- 

 toria sp. and Anabaena sp., Germany. No zoospore discharge observed. 



2. Sorokin (1883: 19, fig. 12), as Phlyctidium globosum on diatoms, 

 "Cladophorae," European Russia. No zoospore discharge observed. 



3. Dangeard (1888c: 142, pi. 5, figs. 16-18), on Glenodinium, France. 

 Probably a new species. 



4. Dangeard (1889b: 62, pi. 3, fig. 16), on Vampyrella sp., France 

 See Rhizophydium vampyrellae (Dang.) Minden, page 252. 



5. Dangeard (1887a: xxiii; 1889b: pi. 3, figs. 12-13), on Chlamy- 

 domonas, Phacotus, etc., France. The fungus on Chlamydomonas is 

 probably a new species. 



6. De Wildeman ( 1 890 : 20), on Melosira various, Belgium. Spo- 

 rangium spherical, about 16ij. in diameter; escape of the zoospores 

 not observed; appeared to be seven zoospores within the sporangium, 

 each about 5 ;x in diameter. 



7. De Wildeman (1891: 170), on Hyalotheca sp., Penium sp., Stau- 

 rastrum sp., Belgium. Only the sizes of the sporangia are given (12.5- 

 23.5 \x in diameter). 



8. De Wildeman (1894: 157), on Melosira sp., France. Record only. 



9. H. E. Petersen (1910: 552, fig. 24c). Petersen records it on Penium, 

 possibly also on other desmids, Denmark. The substratum of the fungi 

 shown in the figure is not given. From the needle-like unbranched 

 rhizoid, the fungus appears closer to Phlyctidium. 



10. Schulz (1923: 181, fig. 13), on Pleurotaenium trabecula, Danzig. 

 Sporangium spherical; rhizoids branched; no zoospore discharge ob- 

 served. 



11. Graff (1928:160), on diatoms, United States. Sporangium 

 spherical, 25-40 \x in diameter; zoospores escaping through a large 

 terminal opening; rhizoids "similar in development to those of R. 

 sphaerocarpum (Zopf) A. Fisch." Probably referable to Rhizophydium 

 sphaerocarpum. 



