LAGENIDIALES 1005 



Lagenidium humanum Karling 

 Mycologia, 39: 225, figs. 1-39. 1947 

 (Fig. 82 F-G, p. 1004) 



Thallus coarse, extensive, richly branched, at maturity septate and 

 slightly constricted at the septations, rarely one-celled, 4-20 \i in 

 diameter; sporangia elongate (4-7 by 15-200 \i), subspherical (15-30 jx), 

 oval (10-15 by 18-30 fx), oblong, lobate, or irregular, with a single dis- 

 charge tube; zoospores reniform, 3.5-4.5 by 7.5-8 [x, biflagellate, typi- 

 cally formed at the orifice of the discharge tube in a vesicle, cystospores 

 spherical, 6-7.5 [x in diameter; gametangia poorly differentiated, the 

 receptive and contributing segments of variable size and shape, elongate 

 (5-7 by 15-22 [x), oval (10-15 by 18-25 [x), subspherical (10-25 fx), 

 narrow, fusiform or lobed, the contents of the male gametangium 

 passing through a simple pore into the receptive segment; oospore 

 hyaline, smooth-walled, spherical (10-18 \i), oval (8-12 by 14-17 ;x), or 

 oblong, germination not observed. 



Saprophytic on human skin used as bait, Karling (loc. cit.)', Karling 

 (1949a: 275), United States; from soil, substrate?, Gaertner (1954b: 

 22), Northwest Africa. 



Although the thallus of this species is elaborately developed, the sex 

 organs are of a primitive type and resemble those of Myzocytium. 



Karling cultivated the species on a peptone-dextrose-yeast-extract 

 medium on which it grew well. He concluded, therefore, that it was not 

 strictly keratinophilic. 



Lagenidium giganteum Couch 



Mycologia, 27: 376, figs. 1-19. 1935 



"The main hyphae are segmented, being constricted or not con- 

 stricted at the septum, the segments sometimes separating from each 

 other; branched. When growing on a copepod. Daphne, or mosquito 

 larva, the large segmented hyphae are within the host, but numerous 

 delicate hyphae extend from the host for a distance of one or two 

 millimeters to form a fringe which has much the appearance of a 

 delicate species of Aphanomyces. Hyphae 6-40 jx thick, the segments 

 50-300 tx long. The hyphal walls contain cellulose giving a purplish 



