462 AQUATIC PHYCOMYCETES 



KEY TO THE SPECIES OF CLADOCHYTRIUM \ 2 



Rhizoidal system bearing septate turbinate cells or septate swellings 

 Sporangium smooth-walled 

 Zoospores with a colorless globule 



Zoospores 4.5-5.5 y. in diameter C. tenue, p. 462 



Zoospores 11 \l in diameter C. taianum, p. 463 



Zoospores with a cadmium-orange or golden-brown globule 



C. replication, p. 464 



Sporangium bearing simple or branched setae C. setigerum, p. 466 



Rhizoidal system bearing swellings of various shapes which, save in 

 formation of resting spores, are nonseptate 

 Zoospore with a single conspicuous globule 



Rhizoidal system coarse, with numerous trabeculae; zoospores 

 4.9-6 [jl in diameter, globule 2-2.75 (x; resting spores inter- 

 calary formed in simple swellings of rhizoids . . C. crassum, p. 467 

 Rhizoidal system more delicate, without trabeculae; zoospores 

 8-10 pi in diameter, globule 4-7 \i in diameter; resting spores 

 formed as an outgrowth of a cell proliferated from a fusiform 



swelling C. hyalimon, p. 468 



Zoospore with numerous golden-brown granules . . C. granulation, p. 469 



CLADOCHYTRIUM TENUE Nowakowski 



Cohn, Beitr. Biol. Pflanzen, 2: 92, pi. 6, figs. 6-13. 1876 

 (Fig. 30 I, p. 474) 



Sporangia intra- or extramatrical, terminal or intercalary, formed 

 from a swelling of the rhizoid or by enlargement of a segment of a 

 septate turbinate cell, whereupon the sterile segment either remains at 

 the base as an empty appendage or eventually becomes a sporangium, 

 up to 66 \i in diameter, spherical, 8-30 \i, or somewhat pyriform, 

 broadly oval or slightly citriform, 8-18 by 10-22 jjl, with a low papilla 

 or more or less prolonged regular or irregular rather stout discharge 

 tube (rarely several) the tip of which is either extramatrical or pene- 

 trates a neighboring cell, wall smooth, colorless, proliferating, the 

 secondary sporangia smaller; rhizoidal system extensive, main axes 

 1.5-3.5 [x in diameter, branching, with spindle-shaped, elongate, 5-8 



1 Cladochytrium aneurae Thirumalachar (Trans. Brit. Mycol. Soc, 31: 8, rigs, 

 1-3, 1947), which has been described from the liverwort Aneura from India, is not 

 said to be aquatic. 



2 See also recently described taxon, p. 470. 



