110 FRESH-WATER ALG^ OF THE UNITED STATES. 



DRAPARNALDIA BAVENELII, Wolle. 



Cells of filaments and primary branches hyaline, as long 

 as wide, or shorter ; constricted at the joints ; matured plants 

 furnished at every joint with 2, 3, sometimes 4, fasciculate 

 branches spherical in outline ; branchlets radiating, yellow- 

 ish green color. Younger stems almost nude, only here and 

 there a very small fascicle, barely as wide or less than the 

 diameter of cells ; apices of branchlets acute. 



Diameter of cells of larger stems, 150-170 // ; f-1 diameter 

 long. 



Diameter of cells of smaller stems, 60-100 // ; 1-1}- diam- 

 eter long. 



Diameter of cells of branchlets of fascicles, 6-8 )JL ; \-l 

 diameters long. 



A very large and distinct new species; the fascicles of 

 branchlets short, radiately spreading, seldom exceeding the 

 diameter of the filament to which they are attached; the 

 central cells of the fascicles longer than broad, those of ends 

 only half as long as broad and seem to be of a microspor- 

 angial character. 



Collected by H. W. Bavenel, in sluggish water, July, 1881, 

 at St. John's Berkley, South Carolina. 



Plate XCV, parts of two steins and an arm, with the 

 fascicles. 



Genus 17, STIGEOCLONIUM, Kg. 



Filaments articulate, simply branched ; in size and general 

 appearance the stems and branches are barely separable ; green ; 

 branches not in fascicles ; attenuated and often ending in a color- 

 less bristle ; cell membrane very thin and hyaline ; cell contents 

 with the chlorophyl scattered or arranged in transverse bands as 

 in Dratparnaldia. Besting spores developed in the cells of the 

 branches, one in a cell. 



Zoogonidia (microzoospores) formed by the division of the 

 cell-contents, 4-16 in a cell, each furnished with four vibratile 

 cilise. 



STIGEOCLONIUM TENUE, Kg. 



Bright vegetative green, variable in size, 4-50 mm long; 

 lubricous ; filaments somewhat branched ; branches simple ; 

 cells 1-3 times longer than broad, often slightly constricted 

 at the joints; branchlets scattered, shortened, nearly erect, 

 subulate, apices acute, but not ending in setae. 



