122 



THE LOWER FUNGI— PHYCOMYCETES 



1927; Graff 1928). The following additional species have been 

 referred to the genus. 



M. megastomurn De Wildeman— in Closierium and Spirotaenia. 

 M. vermicolum (Zopi) Fischer — in Anguillulidae. 



M. (?) irregulare Petersen (perhaps a species of Lagenidiurn)^\\\ Costna- 

 riurn and Micrasterias. 



Fig. 45.- — Lagcnidium rahenhorstii Zopf in vegetative cells of Spirogyra. (a) 

 Infecting swarmspores. (b) Young non-septate thallus developed from swarm- 

 spore, (c) Septate thallus. (d, e) Cells of thallus functioning as sporangia 

 (sp.), antheridia (A), and oogonia (0). (J-h) Swarmsporo formation. {After 

 Zopf 1884.) 



3. Lagenidium Schenk (Verhandl PJnjs. Med. Gesell. Wiirzhurg, 



9: 27, 1857). 



The mature thallus in Lagenidium is an irregular tube, more 



or less branched or provided with protuberances. Septa divide 



the thallus at indefinite intervals into cells, but prominent con- 



