— 430 — 



filaments arising from its apex. Several times I found vegetative my- 

 celium of a Sapromyces-sliaped species with the zoosporangia cylindrical 

 as shown in Fig. V. 



21. Pythiomorpha gonapodyides sp. nov. ; cf. diagnosis page 391. 



23. Pythium Daphnidarum sp. nov. ; cf. diagnosis page 394. 



25. Pythium undulatum sp. nov. ; cf. diagnosis page 394. 



27. Blastocladia Pringsheimii Reinsch. 



I have found individuals with unbranched or more or less branched, 

 short and thick basal cell and other much branched with cylindrical 

 branches. The zoosporangia were more or less cylindrical. 



28-— 29. Gonapodya siliquceformis (Reinsch) Thaxter and Gona- 

 podya polymorpha Thaxter. 



According to Thaxter these species are well defined; but, provided 

 that the forms, I have met with here in Denmark, what I do not doubt, 

 can be referred to both species, I must admit that they are closely re- 

 lated to each other by many transition forms. Perhaps they must be 

 united to one species. I have not observed any sexual organs. 



To the Lagenidiineae I refer 4 families, characterized by their zoos- 

 pores having two flagellar Lagenidiaceae, Sirolpidiacea^, Pontismaceae and 

 Pseudolpidiacete. The Sirolpidiacese and • Pontismacese ^) are not repre- 

 sented in freshwater. 



33. Lagenidium Zopfii. 



It is admitted to be somewhat doubtfull whether the identification of 

 the form in my material (Lyng S0, Silkeborg, Jutland) with this species 

 may be right. I have only seen vegetative stages. 



36. Myzocytium proliferum Schenk and 37. Myzocytium irregu- 

 lare sp. nov. ; cf. diagnosis page 403. 



Generally both forms growing in thread-Algge as well as in Desmi- 

 diaceae are referred to this species. However there is a distinct difference 

 between these forms. Setting aside the different number of the zoo- 

 sporangia, the form of the zoosporangia is different so that the species in 

 the Desmidiacese always consists of irregular zoosporangia. The irregula- 

 rities are thus such that they must be considered as not formed by the 

 lumen of the Desmidiaceae. That is particularly evident when the Myzo- 



cf. my paper 1905. 



