Key to the Species 

 1. Cells 2-4m wide - 2 



1. Cells S-S/x wide _.__ S. subtilis 



2. Cells 2-3.5m wide, 3-8^ long .„ ...__. _ S. bacillaris 



2. Cells 3-4ai wide and up to 30/j. long S. scopulinus 



Stichococcus bacillaris Naegeli 1849, p. 77 



PL 6, Fig. 5 



Filaments composed of short cylindrical cells very slightly con- 

 stricted, if at all, at the cross walls. Chloroplast a pale green parietal 

 plate or folded disc covering a small portion of the wall. Cells 

 2r-S.5fx. in diameter, 3-8/a long. 



On moist, aerial substrates, associated with other algae to form 

 films on floating wood, etc. Mich., Wis. 



Stichococcus scopulinus Hazen 1902, p. 161 

 PI. 6, Fig. 6 

 Filaments of relatively long cylindrical cells without constrictions 

 at the cross walls. Chloroplast a long, folded plate with an indistinct 

 pyrenoid. Cells 3-4/a in diameter and up to 30|U, long. 



Our specimens are questionably assigned to this species. Hazen 

 (I.e.) described the species as growing in dark green skeins on 

 dripping rocks. It has not been possible to differentiate it clearly 

 from S. bacillaris forma confervoidea Hazen (I.e., p. 60), except 

 that the cells in S. scopulinus average slightly wider. 



On stones and moist soil, forming small green patches. Mich., Wis. 



Stichococcus subtilis ( Kuetz. ) Klercker 1896, p. 103 



PI. 6, Figs. 7, 8 



Filaments very long, composed of rather stout, cylindrical cells 

 without constrictions at the cross walls. Chloroplast an elliptical 

 parietal plate with 1 pyrenoid. Cells 5-7-(8)/i, in diameter, 7-20/i, 

 long. 



In shallow water of beach pools and lake margins. Mich., Wis. 



GEMINELLA Turpin 1828, p. 329 



Filaments unbranched and uniseriate, composed of spheroidal, 

 broadly ovoid, or short cylindrical cells inclosed by a wide gelat- 

 inous sheath and usually separated from each other; daughter cells 

 approximated for some time after division to give a paired arrange- 

 ment. Chloroplast a parietal folded plate, with 1 pyrenoid. 



[99] 



