CLASSIFICATION OF FOSSIL FUNGI 481 



cetes in the Cladochytriaceae. These fungi occurred in shell frae;- 

 ments of Mollusca, Foraminifera, and Ostracoda and in sponge 

 spicules of species that date back to the Cambrian. Renault and 

 Bertrand (1885) would include their chytridiaceous Grilletia 

 sphaerospermii in this class. 



1. Oochytriaceae 



Oochytrium * lepidodendri Renault, in twigs of Lepidoden- 

 dron, like the present-day chytrid genus Urophlyctites oliverianus 

 Magnus (1903), is parasitic in leaves of Alethopteris aquilina. 

 Urophlyctites stigmariae Weiss is parasitic in rootlets of Stigmaria. 



2. Pythiaceae 



Pythites dysodilis Pamp., fossil remains from the Miocene, show 

 mycelia and spores. 



3. Peronosporaceae 



Peronosporites antiquarius W. Smith, in tracheids of Lepido- 

 dendron from the English Coal Measures, is one of the best- 

 known fossil fungi. Peronosporites gracilis Renault was first 

 described as Palaeomyces gracilis. Ellis (1918) noted its intracel- 

 lular hyphae in parenchyma cells of stem and roots of Lepido- 

 dendron acideatum and Ly ginodendron old hafnium. Peronospo- 

 rites miocaenicns Pamp. and P. siculus Pamp. are from the 



Miocene. 



4. Mucoraceae 



Mucorites cambrensis Renault from the Paleozoic lacks repro- 

 ductive structures; hence its relationship is unsatisfactorily known. 



Phy corny cites frodinghamii Ellis from the Jurassic is interpreted 

 as having had a chemotactic affinity for iron, as have modern iron 

 bacteria. 



III. ASCOMYCETES 



Approximately 100 species of Sphaerites are included in Meschi- 

 nelli's "Fungi Fossiles," a fact which gives an indication of the 

 abundance of fossil Ascomycetes and at the same time may be pre- 

 sumed to demonstrate the difficulty of making specific identifi- 

 cations. It is reasonable to assume that certain of this assemblage 

 may not be distinct species. There is reason to believe also that 



* Some palaeontologists have not chosen to employ the termination "ites." 



