ULOTHRIX. 1 37 



ULOTHRIX OSCILLARINA, Kg. 



Beautiful green, mucous ; diameter of articulations, 10- 

 12 yw, length one-half or one-third as much ; membrane thin, 

 colorless. 



From lake, Wisconsin. 



Syn. Conferva oscittatoroides, Ag. 



Plate CXYIII, figs. 34-36. The similarity of character 

 between this form, of which we received but few specimens, 

 and such as are represented Plate CXXI, figs. 16, 17, and 

 Plate CXXIV, figs. 11, 13, 15, 16, does not leave the position 

 given to this plant without question of doubt. 



ULOTHRIX MURALIS, (Ag.) Kg. 



Filaments somewhat rigid, thickish, tortuous, very long, 

 interwoven in a bright, grass green stratum ; almuli strongly 

 defined (Harv.). Kuetzing found this plant often furnished 

 with braiichlets and called it U. radicans. Diameter of fila- 

 ments 7-9 ju. Articulations equal, to or as long as wide. 



Found on walls, shaded rocks or in flowing waters. Har- 

 vey reports it from pools of fresh water, Whalefish Islands, 

 Davis Straits. , 



Syn. Conferva velutina, Bory; C. muralis, Dillw. ; Oscillaria pari- 

 etina, Yauch. ; 0. muralis, Ag. 



Terrestial forms, on shaded and moist earth ; Hormidium, Kg. 



ULOTHRIX (Hormidium) FLACCID A, Kg. 



Articulations equal, or twice as long as the diameter, 

 membrane very thin, colorless ; filaments fragile. Cell con- 

 tents usually on one side of the walls, hemispherically con- 

 tracted. 



Diameter of filaments, 7-9.5 //. 



On exposed river stones, old straw, etc. 



Plate CXVIII, figs. 27, 28, represents this species as well 

 as U. subtilis. 



ULOTHRIX (Hormidium) NITENS, Menegh. 



Filaments loosely or densely interwoven, dark green, 

 sometimes forming a somewhat membranaceous, shining 

 stratum. 



Diameter of cells 6-7 /*, as long as wide, or slightly longer. 



