1008 



AQUATIC PHYCOMYCETES 



infected but only about 14 per cent of the crabs were actually so 

 affected Up to 80 or 90 per cent of the crabs in a sample had some 

 degree of infection. The fungus developed abnormally in fresh pond 

 water whereas in salinities varying from 5 to 30 p. p. t. development 

 proceeded rapidly, indicating a strong tolerance to changes in salt 

 concentration. Under laboratory conditions favoring very rapid trans- 

 mission of infection, the eggs of the oyster and of mud crabs were also 

 attacked. 



IMPERFECTLY KNOWN SPECIES OF LAGENIDIUM 

 ? Lagenidium ellipticum de Wildeman 1 

 Ann. Soc. Beige Micro. (Mem.), 17: 8, pi. l.figs. 1-11. 1893 

 Thallus consisting of a single irregularly swollen contorted tabulate 

 tube with filamentous prolongations; zoospores not observed; resting 

 spores ellipsoidal, 20-30 [x long by 10-14 [x wide, with a thick wall 

 provided with irregularly placed blunt protuberances, contents refractive 

 and granular, without a large globule. 

 In rhizoids of mosses, Belgium. 



In de Wildeman's Figure 2 what appear to be two short cylindrical 

 discharge tubes are shown. A thorough investigation of the fungi 

 occurring in this peculiar habitat will probably result in the rennding 

 of this well-marked species. Obviously, further data on the reproductive 

 organs are necessary to place the fungus generically. 



? Lagenidium sacculoides Serbinow 

 Defense des Plantes, 2(2): 84. 1925 

 "Thallus short, unicellular, sac-like with lobes or short branches, or 

 narrowly elongate, 3.5-7.6 p in diameter, with occasional septa. Zoo- 

 spores apparently completing their development in an extramatrical 

 vesicle; spherical, 3.5 ji, in fixed and stained preparations; position and 

 relative lengths of flagella and presence of diplanetism unknown. 

 Sexual reproduction isogamous; contents of two adjacent cells flowing 

 together and forming a zygospore (?) in the space between them. 



1 Not strictly aquatic. 



