CHYTRIDIALES 565 



ly constricted, almost catenulate, up to 20 \x in diameter, much branched 

 and extensive; operculum apical or submerged, shallowly convex, up 

 to 20 [x in diameter; zoospores hyaline, spherical, 5.2-6.2 u. in diam- 

 eter, bearing eight to twenty hyaline refractive granules and a fla- 

 gellum 30-32 jj. long, emerging in a compact mass and soon dispers- 

 ing; resting spore hyaline, smooth-walled, deeply lobed, angular, and 

 irregular in shape, rarely slightly irregular, 7-38 \i in diameter with 

 numerous hyaline refractive globules, functioning as a prosporangium 

 at germination. 



Saprophytic on cellulosic substrata, United States. 



Resembles Karlingiomyces granulatus in its digitate or irregularly 

 stellate sporangial stage but differs in having strongly lobed resting 

 spores. 



MACROCHYTRIUM Minden 



Centralbl. f. Bakteriol., Parasitenk. u. Infektionskrankh., Abt 2, 8:824. 1902; 



Kryptogamenfl. Mark Brandenburg, 5: 385. 1911 (1915); Falck, Mykol- 



og. Untersuch. Berichte, 2(2): 249. 1916 



(Fig. 33 C-E, p. 564) 



Thai! us epi- and endobiotic, monocentric, eucarpic, the epibiotic part 



Explanation of Figure 33 



A. Catenochytridium carolinianum Berdan on decaying wheat; epibiotic 

 operculate sporangium, on upper part of which is attached a portion of spore 

 case, discharging zoospores; catenulate compound apophysis and rhizoids 

 are in substratum. B. Catenochytridium laterale Hanson, discharging sporan- 

 gium bearing basal cyst and large primary apophysate cell and catenulate 

 segments of apophysis which emerge between sporangium and primary apoph- 

 ysate cell. C-E. Macrochytrium botrydioides Minden on submerged fruits: 

 C, empty sporangium with large persistent operculum; D, discharging oper- 

 culate zoosporangium; E, resting spore (?); primary apex appears as kneelike 

 projection on left terminating rhizoidal axis. F-G. Amphieypellus elegans 

 Ingold: F, young and mature individuals on theca of Ceratium (dotted line); 

 G, discharging sporangium showing hinged operculum at left of cluster of 

 zoospores. 



(A, Berdan, 1939; B, Hanson, 1946a; C-E, Minden, 1916; F, Ingold, 1944; 

 G, Paterson, in ed.) 



