222 Chaetophoraceae 



tinguishes the form from the species as above interpreted, the ex- 

 pression " fasciculi ovate or broadly lanceolate" indicates an 

 identification with D. acuta. The large diameter (ioo/i) is not 

 inconsistent with many of our specimens of both species, though 

 it is greater than that reported by European authors. 



4. Draparnaldia platyzonata sp. nov. 



Filaments 1-7 cm. long, loosely tufted or solitary ; branches 

 mostly opposite or whorled and horizontal ; fascicles of branchlets 

 set strictly perpendicular to the branch, prominently stalked, broadly 

 orbicular in outline, the branchlets somewhat symmetrically radiat- 

 ing from the summits of the branches of the rachis, sometimes 

 densely crowded, subfusiform, acuminate or setiferous ; cells of 

 larger branches cylindrical, sometimes slightly constricted at the 

 joints, 50-90 //in diameter, in length equal to the diameter, or 

 frequently shorter, chromatophore very wide, always nearly cover- 

 ing the length of the cell and often strongly reticular ; diameter of 

 terminal branchlets 6-11/1 (pi. 41). 



On rocks or sticks, in brooks draining swamps. 



New Jersey: Grantwood, April, 1899 (89), April, 1900 (281), 

 May, 1900(363, type). 



Vermont: Fifield bog, Wallingford, 2 July, 1901 (641). 



This species in certain stages recalls the figure of D. plumosa 

 opposita Lyngbye, Tent. Hyd. Dan. pi. 65A, and resembles the 

 specimens of D. glomerata biformis Wittrock and Nordstedt, Alg. 

 Exsic. 51J. It lacks, however, what seem to be essential char- 

 acters of these two forms, namely, the two longitudinal lines sup- 

 plying the place of a chlorophyll band in the former, and the 

 double character of the filament which gives the name to the latter. 

 Our form is always easily recognizable by its short cylindrical cells 

 with their broad chromatophore, and by the horizontally set, rosette- 

 like, stout-stalked fascicles of branchlets. Though the chromato- 

 phore of D. glomerata and D. plumosa is sometimes described as 

 a reticular band, it might better be called perforate, while that of 

 D. platyzonata attains the maximum of a truly reticular structure. 

 This species is more distinct from D. glomerata than the members 

 of the D. phunosa-acuta-glomerata series are from one another. 

 This view has been confirmed by repeated collections from the type 

 station and by cultures of that material. 



