332 FRESH-WATER ALG^ OF THE UNITED STATES. 



GLOEOCAPSA RALFSIANA, (Harv. ) Kg. 



Thallus gelatinous, dark purple brown ; tegument intense 

 purple brown ; cells light aeruginous. 



Plate OCX, figs. 29-31, merely a change of color. 



GLOEOCAPSA SHUTTLEWORTHIANA, Kg. 



Thallus gelatinous, dark rufous brown, tegument thick, 

 orange red to pale orange, rarely colorless ; cells pale aeru- 

 ginous. 



GLOEOCAPSA SANG-UINA, ( Ag. ) Kg. 



Thallus effused, gelatinous, blood red, becoming blackish 

 brown. Tegument intense blood red, in the middle pale 

 red, extremes colorless ; cell aeruginous. 



Plate OCX, figs. 29, 30, another change in color. 



GLOEOCAPSA RUPESTRIS, Kg. 



Thallus dark brown, crustaceous, rather hard. Tegument 

 thick, lamellose, yellow, golden brown, or becoming pale 

 and colorless ; cells aeruginous. 



Figs. 27, 28. 



GLOEOCAPSA ARENARIA, Kab. 



Thallus mucous, somewhat olive colored. Tegument 

 thick, spherical, colorless, somewhat lamellose ; lamella 

 diffluent. Cells aeruginous. 



Plate OCX, figs. 22, 28, well represent the form of this 

 condition. 



GLOEOCAPSA ATRATA, Kg. 



Thallus crustaceous, mucous, black. Tegument thick, 

 hyaline ; 2-3 times broader than the central, aeruginous cell. 



Plate OCX, figs. 27, 28, differing in thallus from others- 

 older conditions. 



GLOEOCAPSA SPARSA, Wood. 



Scattered in a mucous stratum composed of various algae. 

 Inner tegument yellowish brown, rarely colorless or lamel- 

 late ; external tegument achromatic, scarcely visible. 



Plate OCX, figs. 29-31, only another condition of 

 6r. magma. 



Beside these forms 1 find notes scattered on the pages of 

 my Sketch-books, covering observations for more than ten 

 years, of at least ten to twenty more forms identified with 



