^9■i University of California Publications. [Botany 



Cylindrospermum sp. ? 



In a specimen colJected floating on a small ])()nd near Coupe- 

 ville, Whidbey Island, Wash., by Gardner (No. 606), the spores 

 are nnripe, but the filaments have heterocysts at both ends. It 

 probably belongs to C. lichpni forme (Bory) Kuetzing. 



Family SCYTOXEMATACE.^^: . 



Microchaete tenera Thuret. 



Forming grayish tufts on drii)ping rocks. Walls of Amaknak 

 Cave, Amaknak Island, Bay of Unalaska, Alaska, Tr.A.*S'. <i)i<J 

 A.A.L., No. 8292! 



The heterocysts are chiefly basal, l)ut there are occasional 

 oblong intercalary ones. The general aspect is that of a 

 Calothrix, but it lacks any indication of a terminal hair. 



Microchaete robusta Setchell and (lardner sp. nov. 



In tufts and stellate clusters on water weeds; filaments 

 elongated and perfectly cylindrical, decumbent at the vei-y ])ase, 

 but scarcely thickened, 16-18 /x in diameter; trichome com])osed 

 of cells which are quadrate or slightly longer than broad in tlie 

 lower portion and which are shortened to one-third as long as 

 broad in the upper ])art, 12 /^ in diameter and the cells 6-16 /^ 

 long, aeruginous and filled with fine granules; sheath thin, at 

 first, but later stratified, hyaline; heterocysts basal and inter- 

 calary, the former lieing spherical or neai'ly so, while the latter 

 are elongated aud rectangular. 



Ill ])onds of fresh water. Xenr Seattle. Wash.. Professor 

 T. C. J>. Killed id. Xo. 76S! 



Apparently a very distinct species, and referred to this 

 genus rather than to Calotrhix, on account of tlie filaments being 

 of uniform width from base to apex. The terminal cells of tlie 

 filaments are short and torulose, and the ui)i)ermost cells are 

 nearly if not quite colorless, reminding one of the terminal hair 

 of the Rivnlariacea?, but the colorless j^ortion of trichome does 

 not taper at all. 



