— 438 - 



53. Siphonaria variabilis H. E. Petersen; common on the tegu- 

 menta of the nymphae of the Phvyganese; cf. my paper 1903. 



55. Rhizoclosmatium globosum H. E. Petersen; common on the 

 above named tegumenta; cf. my paper 1903. 



56. Asterophlyctis sarcoptoides H. E. Petersen; rare on the above 

 named tegumenta; cf. my paper 1903. 



57. Phlyctochytrium Schenkii (Dangeard) Schroeter. 



I have observed the resting spores (Fig. XXII, g). They are globose 

 with thick, smooth membrane and are formed by the endophytic part of 

 the zoosporangia. 



58. Phlyctochytrium stellatum sp. nov. ; cf. diagnosis pag. 417. 

 The manner of the coming out of the zoospores is peculiar. When 



the zoospores are ripe, a vesicle as shov^m in Fig. XXII a and d is formed 

 laterally. The zoospores penetrate through on orifice in the lowest part 

 of the extramatrical part of the zoosporangium. 



62. Rhizophidium septocarpoides sp. nov. ; cf. diagnosis page 420. 



65. Pleotrachelus Wildemani sp. nov.; cf. diagnosis page 422. 



68. Olpidium decipiens (A. Braun) a mihi. 



1 have referred the Rhizophidium decipiens to the genus Olpidium. 

 I have not seen any rhizoids, but I am not sure that my observations 

 are conclusive. This species can at all events not be considered as a 

 genuine Rhizophidium. 



Pleolpidium ? Thaxter mentions a parasite in Blastocladia as Rozella 

 (Bot. Gazette 1896, pag. 50); I have observed a similar form but I may 

 say, that I do not know why this form must be referred to Rozella. I 

 may believe that we here have a Pleolpidium. Owing to insufficient 

 material I have not been able to examine this species more closely. 



70. Woronina polycystis Cornu. 



I have observed in Achlya-hyphae a Woronina similar to the form 

 of Cornu, and I do not hesitate to refer this form to Woronina polycystis. 

 A special form (f. scalariformis) (fig. XXVIl, a) is described as difYering 

 from the gennine Woronina by the formation of zoosporangia in single 

 series and by the fact that the zoosporangia are placed closely to the 

 membrane of the host. 



