Stichococcus 161 



lutely to connect the two in life history ; but as there is every 

 reason to believe that this is only a form which has beenvfavored 

 by a more abundant supply of water, we feel obliged to make this 

 disposition of it As it is a generally distributed, though not 

 abundant form, one may better call attention to it than ignore it. 



2. Stichococcus scopulinus sp. nov. 



Filaments forming long, bright green, lubricous masses ; cells 

 cylindrical, not constricted at the dissepiments, 3—3.5 // in diameter, 

 1- 10 times as long : cell- wall very thin : chromatophore narrow, 

 pale green, without a distinct pyrenoid : asexual reproduction, by 

 means of a single zoospore formed in each cell, more frequent 

 than the vegetative mode (pi. 22, f. 4—6). 



Hanging in skeins from dripping rocks, Morningside Park, 

 New York, April (263, 321A, 285, 353 A A, 530- 



This species is distinguished from Stichococcus bacillaris f. con- 

 ferviodea usually by longer cells, and by its manner of growth in 

 long dense masses of straight filaments instead of in scattered, 

 crisped filaments or small floccose masses, as in that form. 



It is usually abundant at the type station during the winter and 

 early spring. Later it gives way to 5. subtilis, but careful and re- 

 peated observations have furnished convincing evidence that it is 

 not a young stage of that plant, but a distinct species. 



Stichococcus scopulinus does not long persist in the filamentous 

 state when brought into the laboratory ; very soon it either breaks 

 up into the coccoid state or forms zoospores abundantly. 



3. Stichococcus marinus (Wille) 



Ulothrix variabilis Kutz. (?) forma marina Wille, Dijmphna- 

 Togtets Zool.-bot. Udbytte, 8y.pl. ij.f. 8. 1885. (?) 



Filaments dark green ; cells cylindrical, 5-6 fi in diameter, 1-2 

 times as long ; chromatophore a roundish or oblong plate, pyre- 

 noid indistinct. 



One zoospore is formed in a cell and escapes through a small 

 round aperture (J>1. 21, f. 8, p). 



Exsic: Phyc. Bor. Am. 613. Ash Creek, Bridgeport, Conn., 

 August, 1895 (I. Holden), incorrectly quoted as U. variabilis 

 Kutz. var. marina Wille, Rhodora, 2 : 12. 1900. 



In tangled masses about culms of Spartina, in company with 

 Ulothrix implexa ; bank of Yellow Mill Pond, Bridgeport, Conn., 



\ 



