LAGENIDIALES 989 



The fungus found by Couch apparently lacks the thick-walled forcing 

 apparatus. 



Lagenidium enecans Zopf 



Nova Acta Acad. Leop. -Carol., 47: 154. 1884 



Thallus completely tubular, 6-12 u. in diameter by 37-156 u. long, or 

 with a few short broad finger-like branches, sometimes somewhat 

 contorted and saccate, the infection tube persistent, transformed into 

 a single sporangium, the discharge tube cylindrical, 3-6 \x in diameter 

 by 9-36 (x long, prolonged only slightly extramatrically, forming a thick- 

 walled forcing apparatus between the girdle plates; zoospores grape- 

 seed-like, biflagellate, 8-12.5 \x long by 5.7 \x broad, produced in a 

 vesicle at the orifice of the discharge tube, movement rapid, irregular; 

 plants dioecious, gametangia resembling (?) the sporangia; resting spore 

 probably formed after fusion of the contents of a female gametangium 

 with those of an adjacent irregularly spherical male gametangium, 

 filling (?) the receptive gametangium, spherical, 18 \x in diameter, 

 broadly ovoid or irregular and with strongly indented contour, 15-22 

 by 20-24 \x, with a smooth thick wall, a large central lustrous fat globule, 

 and from one to several bright spots in the finely granular contents, 

 germination not observed. 



In Stauroneis phoenicentron, Cocconema lanceolatum, Pinnularia spp., 

 Zopf (Joe. cit.), Germany; (?) diatom, de Wildeman (1893a: 9; 1893b: 

 44, pi. 4, fig. 32), Belgium; Cymbella gastroides, Pinnularia viridis, 

 Amphora oralis, Cymatopleura solea, Stauroneis phoenicentron, Scherffel 

 ( 1 902a : [1 06] ; 1 925a : 20, pi. 2, figs. 60-69), Hungary ; Navicula cuspidata, 

 N. cuspidata var. ambigua, Stauroneis phoenicentron, Skvortzow(1925: 

 433), Manchuria; Cymbella cistula, Friedmann (1952: 209, fig. 7), 

 Austria. 



The species was only briefly described by Zopf, and not figured. Most 

 of our knowledge of it rests on the investigations of Scherffel. Cook 

 (1935: 78) states that the sexual organs were observed by de Wildeman 

 (loc. cit.), but the latter merely mentioned having found an organism 

 possibly referable to this species and gave one figure of an empty spo- 

 rangium. In what he considered this species, Friedmann (1952) observed 

 in one instance the formation of primary anteriorly biflagellate "drop- 

 like" zoospores (6 y. long by 12 \x broad) which encyst. 



