178 Ulothricaceae 



as long ; chromatophore rather dense, covering most of the outer 

 cell-wall; akinetes S—n/t in diameter, globose or flattened (/>/. 

 2 4 J. 8-1 1). 



Exsic: Microspora floccosa Tild. Am. Alg. ijoB, Vancouver, 

 1898. (?) 



In brooks and stagnant pools. 



New York: Van Cortlandt Park, April (288, 348B), May 

 (415B, 600, type), June (633); Botanical Garden, May (376B) ; 

 East Chester, May (393 B) ; Staten Island, April (332). 



New Jersey: Hudson Heights, May (436), October (501); 

 Grantwood, April (530D), May (283C, 429B, 579B) ; Under- 

 cliff, May (5 73 A). 



In respect of size, this species is similar to M. stagnorum, but 

 it is always distinguished from the latter by the slight tumidity 

 of the cells, and the more homogeneous character of the chro- 

 matophore. This seems at first sight like a somewhat superficial 

 distinction, but in the type station, where it grows unmixed with 

 any similar species, it has maintained a most constant character, 

 and has always appeared so distinct that the only reasonable 

 course is to regard it as a new species. 



The larger forms of Microspora tiimidula might possibly be 

 identified with the M. floccosa of Kiitzing, Rabenhorst and Hans- 

 girg, but as has been previously stated, this is probably not the 

 true M. floccosa. 



9. Microspora quadrata sp. nov. 



Filaments light green, often in floccose masses ; cells cylin- 

 drical, not at all constricted at the dissepiments, 5.5— 7 fi (usually 

 about 6.5 p) in diameter, their length equal to the diameter or 

 half as great ; cell-wall very thin ; chromatophore often covering 

 the dissepiments as well as the outer wall, in an even, finely granu- 

 lar sheet {pi. 24,/. 14, 75). 



Forming yellowish-green or sordid floccose masses, or fine 

 cespitose growths, in springs, rivulets and watering-troughs. 



Vermont : St. Johnsbury, winter culture (669) ; July (686). 



Massachusetts: Melrose, May 12, 1901 (F. S. Collins, 

 4.001, p. p.). 



Connecticut : Thomaston, May (560). 



New York : Botanical Garden, May (423, type), June (443A), 



