1000 AQUATIC PHYCOMYCETES 



14 jo. in diameter, with a thick smooth wall, germination not observed. 

 In the gametangia of Spirogyra sp., Zopf (loc. cit.), Germany; game- 

 tangia and zygospores of Spirogyra sp., S. grevilleana, coll. Lemaire, de 

 Wildeman (1895b: 102, fig. 3,) France; zygospores of Spirogyra sp., 

 Cook (1932a: 140, figs. 32-38; 1935:77, pi. 3, figs. 26-32), Great 

 Britain. 



Differing from Lagenidium entophytum in its more slender, more 

 regularly branched thallus, very slender discharge tube, and smooth- 

 walled resting spore. Zopf stated that the thallus may extend from one 

 host cell to another, but it is possible that this refers to the discharge 

 tube. 



Lagenidium nodosum (Dangeard) Ingold 

 Ann. Bot. London, 13 (N.S.): 442, figs. 1-4. 1949 

 (Fig. 79 D-E, p. 977) 

 Resticularia nodosa Dangeard, Le Botaniste, 2:96, pi. 4, figs. 24-31. 

 1890-91. 



Thallus somewhat moniliform because of passing through the cross 

 walls of the host, with poorly developed diverticula and occasional 

 cross walls; zoosporangium either a simple segment of the thallus 

 bearing a short discharge tube which extends beyond the sheath of the 

 host, or a strongly inflated diverticulum and external discharge tube; 

 zoospores seven to ten, formed in a vesicle at the orifice of the discharge 

 tube, bean-shaped with two lateral flagella; plants monoecious, the 

 female gametangium an irregular, unmodified segment of the thallus, 

 the male an adjacent segment, fertilization probably accomplished 

 through a simple pore; oospore spherical, smooth-walled, with a large 

 oil globule, germination not observed. 



Parasitic in Lyngbya aestuarii, Dangeard {loc. cit.), France; Lyngbya 

 sp., Ingold (loc. cit.), Great Britain. 



The foregoing description is based upon Ingold' s observations. He 

 (loc. cit.) was certainly dealing with the same fungus as Dangeard and 

 his observations have clarified its relationships. The one observed by 

 Fritsch and ascribed to this species (1903) and ? Resticularia boodle i 

 Fritsch, as previously suggested (Sparrow, 1943:678), are probably 

 mixtures involving Fungi Imperfecti. 



The following two were described as species of Resticularia. 



