556 AQUATIC PHYCOMYCETES 



Saprophytes on vegetable debris. 



Distinguished from Chytridium by the catenulate secondary apophyses. 



KEY TO THE SPECIES OF CATENOCHYTRIDIUM 



Apophysis always compound ; zoospore with a single globule 



Persistent zoospore cyst near apex of sporangium; the latter variable 



in shape C. carolinianum, p. 556 



Persistent zoospore cyst near base of sporangium; the latter regu- 

 larly citriform C. kevorkianii, p. 557 



Apophysis simple or compound ; zoospore with several refractive glob- 

 ules C. laterale, p. 558 



CATENOCHYTRIDIUM CAROLINIANUM Berdan 



Amer. J. Bot., 26: 461, fig. 1. 1939 

 (Fig. 33 A, p. 564) 



"Zoosporangia hyaline, spherical, sub-spherical, pyriform, obovoid, 

 ovoid, elliptical, kidney-shaped or convoluted with pointed lobes, 8-40 

 x8-75u.. Operculum apical to sub-apical in position, hinged to and 

 persistent on the empty sporangium ; orifice circular, 6-20 u, in diameter. 

 Catenulate segments of apophysis 2-30 in number, arranged in 1-4 

 linear series attached to the primary apophysate cell; primary apophy- 

 sate cell commonly spherical to ovoid, 5.5-22 u.; other segments of 

 apophysis spherical, ovoid, elliptical or irregularly elongate, joined by 

 protoplasmic connection through the wall or by an elongated isthmus. 

 Rhizoidal system (including apophysis) 55-800 u. in extent; rhizoids 

 from .5-3 jj. in diameter, becoming very finely branched; branching 

 somewhat dichotomous. Zoospores hyaline, spherical, 5-6 fj., uni- 

 nucleate, with a single highly refractive globule about 2.5 u. in diameter; 

 cilium 35-40 \i in length. Infecting zoospores commonly attached later- 

 ally to wall of host cell. Old zoospore case usually persistent on the zoo- 

 sporangium or resting spore, flattened, hyaline or amber and thick- 

 walled, about 8 (jl in diameter. Treatment with chlor-iodide of zinc 

 producing a pale mauve color in the sporangium wall, a deep mauve 

 in the old spore case, a deep pinkish-mauve in the segments of the 

 apophysis, magenta in the primary apophysate cell, barely affecting the 

 rhizoids. Resting spore smooth, spherical to ovoid, 8-40 u., thick-walled. 



