CHYTRIDIALES 495 



sporangium wall has been noted by Sparrow (1936a) on the fungus 

 parasitizing oogonia of Nitella. It is possible that this is, in fact, another 

 species and it is, therefore, questioned. 



Chytridium acuminatum Braun 



Monatsber. Berlin Akad., 1855: 380; Abhandl. Berlin Akad., 1855: 29, pi. 1, 



fig. 11. 1856 



Sporangium sessile, ovate, ovate-pyriform, or urceolate, 16.6 jj. high, 

 with a distinctly umbonate operculum, wall smooth, colorless; rhizoids 

 and zoospores not observed ; resting spore endobiotic, spherical, smooth- 

 walled, with a single globule. 



On oogonia of Oedogonium rothii, possibly also on O. echinospermum, 

 Braun (loc. cit.), Germany; diatoms, Sorokin (1883:21, fig. 18), 

 Asiatic Russia; zygospores of Mougeotia sp. Cornu (1872a: 121), 

 France. 



Differing from Chytridium olla in the smaller size of its sporangia 

 and the more pronounced umbo on the operculum. Though considered 

 by Fischer and Minden to be only a small variety of C. olla, with a 

 prolonged umbo, further observations should be made on the fungus 

 before it is reduced to synonymy. "Chytridium acuminatum'" of Scherffel 

 (1926a: 225), because of the formation of an endobiotic swelling, 

 appears closer to C. brevipes Braun. Figures of the species are given in 

 Cooke (1882-84: pi. 81, fig. 1). 



Chytridium lateoperculatum Scherffel 

 Arch. Protistenk., 54: 173, pi. 9, fig. 10. 1926 



Sporangium sessile, broadly and symmetrically urn-shaped, 12 \x high 

 by 20 \x wide, with a smooth colorless wall, its broad concave base 

 resting on the rounded wall of the host, opening with a sharply circular 

 split at the dehiscence of a slightly convex large disclike operculum 20 y. 

 in diameter; zoospores and endobiotic system not seen; resting spore 

 not observed. 



On zoocyst of Vampyrella pendula, causing marked disorganization 

 and clumping of the host contents, Hungary. 



