536 AQUATIC PHYCOMYCETES 



in Betula in New Hampshire. Here again, because of the difficulty of 

 freeing the plants intact from their substratum, no complete picture of 

 the vegetative system was obtained. From what was learned, however, 

 this system was filamentous, hyphal, and at least occasionally septate. 

 The sporangia were 17-45 [x in diameter by 20-45 \i high, were ordinarily 

 provided with a broad somewhat attenuated discharge tube, and ter- 

 minated in a smoothly convex or umbonate operculum. The zoospores 

 were posteriorly uniflagellate, with a single globule, and 5-7 u. in diam- 

 eter. Sparrow's form resembles a species of Endochytrium in being 

 within the cells of the substratum and Chytridium xylophilum in the 

 general shape of the sporangia and in the habitat, but if the septate 

 hyphal characters of the mycelium are confirmed by subsequent inves- 

 tigation it probably represents the type of a new genus. 



? Chytridium sp., Schulz 

 Schriften f. Susswasser und Meereskunde, 2 (11): 181, fig. 14. 1923 



Sporangium sessile, spherical, 12-14 \x in diameter, wall thin, the 

 outer surface with a minute spiral crisscross pattern, with two sub- 

 apical convex opercula; rhizoid tubular, unbranched; zoospore dis- 

 charge not observed; resting spore not observed. 



On zygote of a desmid, Germany. 



If the opercula described are not in reality protruding papillae, the 

 form is apparently a new species. Observations on zoospore discharge, 

 however, will have to be made before this can be said with certainty. 



? Chytridium sp., Fott 

 Preslia, 24: 208. 1952 

 Sporangium obovoid, twisted, upright, beneath gradually diminished, 

 broad rounded above, 10-18 jx high by 9-12 u. in diameter, to all appear- 

 ances opening by a fairly large apical operculum; endobiotic subspo- 

 rangial part spherical, 6 \x in diameter. 



Parasitic on Chlorobotrys polychloris, Czechoslovakia. 



EXCLUDED SPECIES OF CHYTRIDIUM 



* Chytridium alarium Kibbe 

 Publ. Puget Sound Biol. Station, 1: 221. 1916 

 Cystidia of the alga Alarium. Not a fungus. 



