SAP RO LEG MI ALES 829 



biotic part, of the rhizoidal system and sometimes an apophysis as well; 

 zoospores formed in the sporangium, liberated as flagellated or non- 

 flagellated bodies, laterally biflagellate when motile; resting stage not 

 observed. x 



Members of this family are unique in combining a typically Chytrid- 

 ////;?-like thallus structure with a saprolegniaceous kind of zoospore. 

 Although so far they are known only from the marine habitat, undoubt- 

 edly fresh-water forms occur. 



Two new species have recently been discovered by Kobayasi and 

 Ookubo (1953), one, the type of a new genus, and the other an addition 

 to Thraustochytrium. Thus, after two decades there comes confirmation 

 of the existence of these bizarre fungi. 



KEY TO THE GENERA AND SPECIES OF THE THRAUSTOCHYTRIACEAE 



Zoospores liberated upon the bursting and dissolution of the distal 



part of the sporangium wall Thraustochytrium, p. 829 



Zoospores at discharge nonflagellated; sporangium internally pro- 

 liferous T. proliferum, p. 831 



Zoospores at discharge emerging as flagellated bodies; sporangium 



not proliferating T. globosum, p. 83 1 



Zoospores liberated upon the formation of an apical sporangial pore ; 



sporangium apophysate Japonochytrium (rnarinum), p. 832 



THRAUSTOCHYTRIUM Sparrow, emend. 2 



Biol. Bulletin, 70: 259. 1936 

 (Figs. 60 D-F, p. 806; 63 C-D, p. 824) 

 Thallus epi- and endobiotic, monocentric, eucarpic, consisting of the 

 epibiotic rudiment of the sporangium derived from the enlarged body 

 of the encysted zoospore and the endobiotic unbranched or branched 

 rhizoidal vegetative system; sporangium liberating the spores upon the 

 bursting and dissolution of the distal part of the wall, internally pro- 

 liferous ; zoospores formed within the sporangium, liberated as nonflagel- 

 late, somewhat angular bodies, becoming flagellate after a period of 

 rest, or as flagellated bodies, the flagella oppositely directed and anter- 

 iorly or laterally attached; resting spores epibiotic, thick-walled, with 

 endobiotic rhizoidal system. 



1 See Johnson (1957c). 



2 See also T. pachydermum Scholz. Arch. f. MikrobioL, 29:359, 1958. 



