Draparnaldia Judayi Prescott 1944, p. 351 

 PI. 16, Figs. 1-5 



Plant invested by a very soft, watery mucilage. Main axis com- 

 posed of slender, slightly inflated or cylindrical cells, with constric- 

 tions at the cross walls. Lateral secondary branches lacking, the axial 

 filament giving rise only to rather simple fascicles of small branches, 

 which are opposite or in whorls, arising at right angles from the mid- 

 region of the axial cells; rachis of the fascicles apparent only in the 

 larger and well developed branches; the apices of most branchlets 

 ending in stout, straight setae, which are often bulbous at the base; 

 setae sometimes arising laterally or dichotomously. Chloroplast a 

 narrow band in the main axial cells, covering most of the wall in 

 the branches. Cells of the main axis 12-15.2/^ in diameter, 30-40)U, 

 long. 



One of the most distinctive characteristics of this species is the 

 whorled arrangement of the very simple and much reduced fascicles 

 of branches, arising from the midregion rather than from the joints 

 of the main axial cells. The position of the branchlet origin suggests 

 Draparnaldiopsis alpinis Smith and Klyver. In that species, however, 

 the stalked fascicles arise from short, differentiated cells in the main 

 filament. Another peculiarity is the form and location of the setae. 

 These may be terminal, 1 or 2 arising from a non-tapered apical cell, 

 or lateral, in which case they may take the place of a dichotomous 

 branch. The setae are similar in morphology to those of Chaetonema. 



Entangled in overhanging grass in a Sphagnum bog pool. Wis. 



Draparnaldia platijzonata Hazen 1902, p. 222 

 PI. 15, Figs. 2, 3 



Axis of thallus with opposite, horizontal branches, composed of 

 cylindrical cells with but slight constrictions at the cross walls; fas- 

 cicles of branchlets opposite or in whorls, set at right angles to the 

 main axis; sometimes with branches distinctly stipitate (the stipe 

 composed of 2 or 3 cells ) and without an apparent rachis. Main axis 

 50-90/x in diameter; cells in the branchlets 6-1 Iju, in diameter. 



In cold ponds and ditches of trickling water. Wis. 



Draparnaldia plumosa (Vauch.) C. A. Agardh 1812, p. 42 



PI. 15, Fig. 4 



Main axis composed of cylindrical cells li/o to 2 times their diam- 

 eter in length, slightly constricted at the cross walls. Lateral fascicles 

 of branches alternate or opposite, at right angles to the main axis or 

 somewhat ascending; fascicles with an apparent axis which extends 



[121] 



