CEDOGONIACE^E. 151 



B. Oogonia furnished with verticellate m edia/i processes . 



a. Oospores snbglobose. 



CE. Itzigsohnii, De By. 



b. Oospores subellipsoid. 



CE. excisum, Wittr. ${ Lund. 



CE. Archerianum. Cke. (Pringsheimianum, Archer). 



Sect. 2. Dioecious species. 



Sub-Sect. 1. Species with dwarf males. 



A. Species with dwarf males unicellular. 



a. Oogonia furnished with verticellate processes in the 



middle. 



CE. platygynum, Wittr. 



b. Oogonia always destitute of median processes. 



a Oospores globose or subglobose. 



CE. Kothii, Le Cl. 

 CE. Areschougii, Wittr. 

 CE. pluviale, Nord. 

 CE. undulatum (Breb,}. 



CE. Beinschii, Roy t 

 /3 Oospores subellipsoid. 



None. 



B. Species bicellular, spermogonia internal, with d?varf males. 



CE. depressum, Prings. 



C. Species mitli dwarf males bi-multicelltdar, spermogonia external. 



a. Oospores even. 



a Oospores globose or subglobose. 



CE. flavescens, Hass. 

 CE. Braunii, Kutz. 

 CE. macrandum, Wittr. 

 CE. crassiusculum, Wittr. 



/3 Oospores ellipsoid or egg-shaped. 



CE. Borisianum, Le Cl. 

 CE. concatenatum, Sass. 

 CE. acrosporum, D. By. 

 CE. ciliatum, Hass. 



b. Oospores echinulate. 



a Oospores globose. 



CE. Cleveanum, Wittr. 

 CE. echinospermnm, Br. 



fi Ooospores ellipsoid. 

 None. 



Sub-Sect. 2. Species dioscious, with elongated male plants, 



a. Oospores echinulate. 



None. 



b. Oospores smooth. 



a Oogonia not, or slightly, swollen. 

 CE. capillare, L. 



