288 AQUATIC PHYCOMYCETES 



male thallus (the latter resembling an early stage in sporangial devel- 

 opment), both (male?) increasing in size, especially the female which 

 eventually receives the content of the male, expands and becomes 

 transformed into a zygote. Germination unknown." (Canter, loc. cit.). 



Parasitic on Apiocystis brauniana, Great Britain. 



The sexual-reproductive process, preceding resting-spore formation, 

 appears to be similar to that of Rhizophydium ovatum (p. 291). 



RECENTLY DESCRIBED TAXON x 



Rhizophydium utriculare Uebelmesser 

 Arch. f. Mikrobiol., 25: 314, rig. 3, 1956 



Sporangium sac- or pear-shaped, rarely spherical, 120 (j. long by 

 80-100 \x in diameter; rhizoid very delicate, little-branched; zoospores 

 globose, 8 jo. in diameter, lacking a globule, the contents granular in 

 the anterior portion, and the remainder hyaline, with a 60-70 \x long 

 flagellum, escaping through three to seven pores formed upon the 

 deliquescence of large prominent papillae; resting spore spherical, 

 25-30 [A in diameter, with a stout smooth wall, contents with small 

 globules. 



Pine-pollen bait, normal soil, Australia; saline soil, United States. 



SECTION III 2 



Rhizophydium clinopus Scherffel 



Abstracts of Communications, V Inter. Bot. Congress, Cambridge, 1930: 222; 

 Arch. Protistenk., 73: 141, pi. 9, fig. 3 a-g. 1931 



(Fig. 17 T, p. 228) 



Sporangium sessile on the raphe of the host, obovoid or obpyri- 

 form, with a broad more or less sharply defined stalklike basal part 

 which is usually inclined somewhat to the long axis of the main body 

 of the sporangium, with which it is continuous, wall smooth, delicate, 

 1 1—24 ijl in diameter by 6-19 (j. high, usually 16-18 \x in diameter by 



1 Not included in the key. 



2 See also the following imperfectly known species of Rhizophydium: 



R. septocarpoides, p. 3 1 3 Rhizophydium sp., p. 3 1 3. 



