968 AQUATIC PHYCOMYCETES 



Sirolpidium bryopsidis (de Bruyne) H. E. Petersen 

 Oversigt Kgl. Danske Vidensk. Selskabs. Forhandl,. 1905(5): 480, fig. 9 

 Olpidium bryopsidis de Bruyne, Arch, de Biol., 10: 85, pi. 5, figs. 1-15. 1890. 



Disarticulated sporangia, 8-90 u. long by 7-16 \x in diameter, olpidioid 

 types 18-38 \i in height by 12-17 jjl in diameter, wall thin, smooth, 

 colorless, discharge tube narrowly cylindrical, up to 165 jjl or more in 

 length, extending for variable distances outside the alga; zoospores 

 narrowly pyriform, somewhat arched, about 4-6 \x long by 2-3 \x wide, 

 the narrow anterior end bearing a refractive granule and two oppositely 

 directed flagella; resting spore not observed with certainty. 



Parasitic or saprophytic in Bryopsis plumosa, de Bruyne (loc. cit.), 

 Italy; Petersen {loc. cit.), Sparrow (1934c: 11, pi. 2, figs. A-H), Den- 

 mark; Bryopsis plumosa, Cladophora sp., Sparrow (1936b: 252, pi. 1, 

 figs. 4, 7, pi. 3, fig. 1), United States; Bryopsis plumosa, Pseudobryopsis 

 myuria, Aleem (1950d:432, figs. 20-22), France; Bryopsis plumosa, 

 Aleem (1953:16, pi. 2, figs. 1, 2), Sweden; Bryopsis plumosa, Cla- 

 dophora japonica, Kobayashi and Ookubo (1953: 61, fig. 7), Japan. 



In the American material infected plants of Bryopsis were recog- 

 nizable macroscopically by the presence of blackened areas along the 

 fronds. The fungus was cultivated to a small extent in dextrose solutions. 

 In 0.5 and 1 .0 per cent solutions in sea water extramatrical hyphae up to 

 112 [x in length were obtained in forty-eight hours. Attempts to grow 

 the fungus on solid media, however, were uniformly unsuccessful. 



Resting spores have not as yet been convincingly demonstrated, al- 

 though de Bruyne figures spherical or ellipsoidal "cysts de conservation" 

 and Petersen has found thick-walled bodies associated with the spo- 

 rangia. Zoospores of the Japanese material were described as nephroid 

 with two laterally attached flagella. 



RECENTLY DESCRIBED TAXON 



Sirolpidium zoophthorum Vishniac 



Mycologia, 47: 641, figs. 1-8. 1955 



Thallus branched, becoming septate; cells containing a large spherical 

 vacuole, 10-15 \i in diameter when young, at maturity up to 82 \i in 



