102 ZYGNEMATACEAE 



outer pectic layer, which may be 7-10/i in thickness; spore wall brown, 

 smooth. (PI. XVI, Fig. 17.) 



British Isles; Sweden; Finland; Latvia; Spain. 



53. MouGEOTiA DisjuNCTA Tfanscau 1934. Trans. Amer. Micros. 



Soc. 53, p. 222, Figs. 50-51. 



V^egetative cells 14-18^ x 50-200^; chromatophore with 2-8 pyre- 

 noids in a line; conjugation scalariform; zygospores in the conjugat- 

 ing tubes, compressed-globose, 24-32 m x 21-28 m; sporangium wall 

 changing during maturity to pectic substance and becoming as much 

 as 25 iu, in thickness and pushing the 2 gametangia apart, but supporting 

 the zygospore within; spore wall chestnut brown, punctate, suture 

 prominent. (PI. XVII, Figs. 7-8.) 



United States: Florida, Fort Myers (Tiffany Coll.); China, Hunan 

 (lao 1940) listed as A/, gelatinosa. 



54. MouGEOTiA oEDOGONioiDES Czufda 1931. Bcih. Bot. Zentralbl. 



48, p. 286. 



Vegetative cells 16-18 /a in diameter, with 1-2 platelike chroma- 

 tophores, each with 2-3 pyrenoids; conjugation scalariform between 

 geniculate cells, lateral by the solution of the cross wall and the devel- 

 opment of a conjugating tube between the ends of the gametangia; 

 subsequently, in both cases, following the union of the gametes, the 

 sporangium wall changes to a thick pectic layer, 8-20 a*^ in width; the 

 gametangial wall at the point of union with the sporangium becomes 

 modified, suggesting the ring scars of Oedogonium cells; zygospores 

 globose or compressed-globose, 41-50/^1 x 40-41 /a; outer wall thick, color- 

 less, smooth; spore wall yellow, thick, and irregularly corrugate, with 

 a distinct equatorial suture. (PI. XVII, Figs. 9-10.) 



Asia, Tibet. 



55. MouGEOTiA CYANEA Transcau 1926. Ohio Jour. Set. 26, p. 321. 



Vegetative cells (i4-)i6-i8(-2o))u. x 160-200 ;ia; chromatophore 

 occupying one-third to one-half of the cell, with 4-10 pyrenoids in a 

 row; conjugation scalariform; zygospores in the conjugating tubes, 

 compressed-spherical, 38-48^11 x 30-40 /a, with the long axis parallel to 

 the filaments; spore wall blue, finely punctate; aplanospores spheroidal, 

 laterally placed in the sporogenous cell, 30-32)", in diameter; both kinds 

 of spores surrounded at maturity with a transparent pectic layer, 4-8 /i 

 thick, which may disappear in preserved specimens. (PI. XVII, Figs. 



15-17-) 



United States: Michigan and Ohio to Texas and Florida. 



