104 



ZYGNEMATACEAE 



60. MoucEOTiA TRANSEAui Colliiis 1912. Tiifls College Studies. 



Sci. Ser. 3, p. 77. Wittrock. Bih. Kgl. Svensk, Vetens}{. 

 Akad. Handl. 1, p. 39. 1872 (as M. tenuis). 



Vegetative cells 9-13 /^ x 50-150 ja; chromatophore with 4-8 pyre- 

 noids in a single row; conjugation scalariform; zygospores globose to 

 triangular-ovoid, 20-30 /x x 26-36//., occupying the middle portion of the 

 receptive gametangium and the tube; spore wall yelknv, smooth; aplan- 

 ospores obliquely ovoid, 12-20/x x 20-32 /x, formed at the middle of a 

 straight or slightly angled cell which may be as long as the gametan- 

 gium or longer. (PI. XVII, Figs. 19-20.) 



United States: Not uncommon from Oklahoma eastward to Massa- 

 chusetts and Florida. 



England; Sweden; India. 



The first of a series of 3 species in which the sporangium divides one of 

 the gametangia but not the other. In many collections of these species there 

 are filaments in which only part of the cells conjugate; the others form 

 aplanospores. Other collections contain only aplansporic filaments. Recently 

 Krieger has listed this species as M. abnorme Kisselev 1927. The figure in 

 Kisselev's publication of 1927 is probably of some other species, since the 

 first structures formed after conjugation are the 3 sporangial walls, and this 

 figure has no sporangial walls. The name M. tenuis Wittrock 1872 was 

 preoccupied by M. tenuis Kiitzing 1849, which proved to be a synonym of 

 M. scalaris Hassall 1842. 



61. MouGEOTiA FLORiDANA Transeau 1934. Trans. Amer. Micros. 



Soc. 53, p. 224. 



Vegetative cells 14-20/x x 60-200 /a; chromatophores with 6-8 pyrc- 

 noids in a single row; conjugation scalariform; zygospores occupying 

 the middle of the receptive gametangia and the tubes, globose to trian- 

 gular-ovoid, 30-40 i". X 36-48 /a; spore wall yellow, smooth; aplanospores 

 obliquely ovoid, 18-24 /x x 30-45 m, occupying the middle part of the 

 cell; spore wall yellow, smooth. 



United States: Oklahoma and Texas eastward to Pennsylvania and 

 Florida. 



Northern India (Randhawa Coll.). 



This species was collected by WoUe at Bethlehem, Pennsylvania, and 

 named M. tenuis (Cleve) Wittrock var. minor. 



62. MouGEOTiA poiNciANA Transcau 1934. Trans. Amer. Micros. 



Soc. 53, p. 224, Figs. 45-46. 

 Vegetative cells 21-25 ju, x 100-200 /it; chromatophores with 6-10 

 pyrenoids in a single row; conjugation scalariform; zygospores occupy- 

 ing the middle portion of the receptive gametangia and the tubes, tri- 

 angular-ovoid to globose, 36-44M X 35-51 /t; spore wall yellow, smooth; 



