480 AQUATIC PHYCOMYCETES 



with occasional swollen appressoria; sporangia pyriform, ovoid, or 

 bursiform, 15-22.5 \i in diameter by 21-24.7 \x long, with a cylindrical 

 attenuated discharge tube (rarely two) 1 20-1 53 \x long by 6 fj. in diameter, 

 tapering to 2 \x at the tip, wall thin or somewhat thickened; zoospores 

 ellipsoidal or pyriform, 1.5 \x in diameter, with a long flagellum and 

 golden-yellow contents. 



In the jelly and between the cells of Calothrix sp., Deckenbach (he. 

 cit.), Russia (marine); Calothrix parasitica, W. H. Weston, Jr., and D. 

 M. Reynolds, Rivularia atra var. confluens, I. Lewis and Weston, 

 in Sparrow (1943: 321), United States. 



Petersen (1906) reported finding this species in fresh-water blue-green 

 algae in Denmark. 



Little is known about the development of the species save that the 

 zoospore upon germination produces two oppositely directed germ 

 tubes. The cross walls do not occur at such frequent intervals as do 

 those of the higher fungi, but rather separate the hyphae into a series 

 of fairly long cylindrical segments. The fungus is remarkable in the 

 possession of a definitely hypha-like vegetative system and chytridia- 

 ceous zoospores. There appears to exist an operculate counterpart of 

 Coenomyces (see Sparrow, 1936a: 432, pi. 15, figs. 22-23) which inhabits 

 decaying twigs in fresh water. 



To afford a resting place for his extraordinary fungus Deckenbach 

 erected a group, the "Coenomycetes," for filamentous fungi with a 

 septate mycelium, reproducing by zoospores. From the type of zoospore 

 germination and thallus, possibly belonging in the Blastocladiales. 



IMPERFECTLY KNOW GENERA OF THE CLADOCHYTRIACEAE 



? NEPHROMYCES Giard 

 C. R. Acad. Sci. Paris, 106: 1180. 1888 

 Vegetative system in the kidney of ascidians, composed of coenocytic 

 strongly entangled delicate filaments, the free ends terminated by sphe- 

 roidal swellings, bearing irregularly cylindrical contorted intercalary 

 swellings which become the inoperculate sporangia; zoospores minute, 

 spherical, with a basal granule and a long delicate flagellum; zygospores 

 formed by conjugation of from four to five filaments, granular or slightly 

 echinulate, upon germination giving rise to two opposite germ tubes. 



