302 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



scanty ramification and the strongly tapering branches resem- 

 bling .S. stagnatile, but with larger cells, branches never opposite, 

 forming dense tufts ; never found in a floating state. 



14. S. minus (Hansg.) uov. comb.; 5". longipilus var. minus 

 Hansgirg, 1886, p. 227 ; P. B.-A., No. 865. Forming dense 

 tufts up to 5 mm. high ; filaments radiating from a palmelloid 

 base, 4-6 fj. diam., cells 2-4 diam. long ; filaments sparingly and 

 irregularly branched, ending in a long hair ; procumbent fila- 

 ments arising near the base of the erect filaments, similar or 

 slightly larger. Mass. 



This plant was found growing on stems of plants in a clay-pit, 

 Medford, Mass., June, 1900. It seems to be the S.longipilus 

 var. minus of Hansgirg, but as pointed out by Hazen, 5". longi- 

 pilus is a plant of much larger dimensions. The small form 

 seems to continue of the same size, not to pass into the typical 

 ^S". longipilus. 



25. DRAPARNALDIA Bory, 1808, p. 399. 



Filaments united by a soft, gelatinous coating, not forming a 

 thallus of definite form ; main filaments attached by basal rhi- 

 zoids, more or less branched, stout, bearing dense lateral fas- 

 cicles of ramuli, much smaller than the main filaments, often 

 setiferous. Chromatophore in the stem and large branches a 

 parietal band, sometimes perforated, with numerous pyrenoids ; 

 in the cells of the ramuli, a layer covering the wall, with few 

 pyrenoids. Asexual reproduction only from the ,cells of the 

 ramuli, by 4-ciliate zoospores with red stigma, germinating im- 

 mediately ; also by akinetes and aplanospores ; sexual repro- 

 duction by conjugation of 4-ciliate gametes, which, however, 

 may germinate without copulation. 



Common plants of running water, chiefly in spring ; distin- 

 guished from Stigcoclonium and Chaetophora by the sharp con- 

 trast between the main stems and the ramuli ; also from Chacto- 

 bhora by the thin, amorphous character of the gelatinous coating. 



KEY TO THE SPECIES OF DRAPARNALDIA. 



i. Rachis of the fascicle of ratnuli distinct throughout. 2. 



i. Rachis of the fascicle of ramuli indistinct. 3. 



2. Fascicles erect, lanceolate, elongate. i. D.plumosa. 



2. Fascicles spreading, broadly ovate, acuminate. 2. D. acuta. 



3. Cells of main branches inflated, chromatophore narrow. 



3. D. glomerata. 

 3. Cells of main branches cylindrical, chromatophore broad. 



4. D. platyzonata. 



