52 A CATALOG OF ILLINOIS ALGAE 



GYROSIGMA Hassall, 1845; Cleve, 1894 



G. ACUMINATUM (Kuetz.) CI. Boyer, loc. ciL, p. 456 (1927); Mills, loc. 



ciL, p. 1149 (1934). 

 Navicula sigma Ehr. 



Eddy 1934, p. 387: Champaign, Mahomet — Sangamon River 

 (July-Dec). Eddy 1927B, pp. 215, 220; Ahlstrom 1936, p. 292: 

 Cook, Chicago, Evanston — Lake Michigan. Bailey 1845, p. 34, 

 as Navicula sigma: St. Clair- — Mississippi River. 



G. ATTENUATUM (Kuetz.) CI. Boyer, loc. cit., p. 455 (1927). 

 Pleuro sigma attenuatum W. Smith 



Babcock 1872A, p. 13; 1872B, p. 104; Briggs 1872A, p. 44; 

 Thomas & Chase 1887, p. 330, as Pleurosigma attenuatum: Cook, 

 Chicago — Lake Michigan. Agersborg 1930, pp. 106, 110, as 

 Pleurosigma attenuatum: Macon, Decatur — warm waste-water 

 ditch (Dec.-Feb.). 



G. EXIMIUM (Thw.) Boy. Boyer, loc. cit., p. 462 (1927); Mills, Index 



Diat., pp. 828, 1332 (1934). 

 Pleurosigma eximium V. H. 



Thomas & Chase 1887, p. 330, as Pleurosigma eximium: Cook, 

 Chicago — Lake Michigan. 



G. KUETZiNGii (Grun.) CI. Boyer, loc. cit., p. 461 (1927). 

 Pleurosigma kuetzingii Grun. 



Thomas & Chase 1887, p. 330, as Pleurosigma kuetzingii: Cook, 

 Chicago — Lake Michigan. 



G. SCALPROIDES (Rab.) CI. Boyer, loc. cit., p. 460 (1927). 



Transeau : Clark — Whetstone Creek (Oct.). Coles Charleston — 

 small stream and ditch (Apr., Oct.). Lawrence, Pinkstaff — pond 

 (Nov.). 



G. SPENCERII (Quek.) CI. Boyer, loc. cit., p. 459 (1927). 

 Pleurosigma spencerii (Quek.) W. Smith 



Babcock 1872A, p. 13; 1872B, p. 104; Briggs 1872A, p. 44; 

 Thomas & Chase 1887, p. 330; Jelliffe 1893, p. 310, as Pleuro- 

 sigma spencerii: Cook, Chicago — Lake Michigan. Galtsofif 1924, 

 p. 405, as Pleurosigma spencerii: Mercer, New Boston— Missis- 

 sippi River, Sturgeon Bay (July). 



G. woRMLEYi (Sulliv.) Boy. Boyer, loc. cit., p. 460 (1927). 

 Pleurosigma wormleyi Sulliv. 



Thomas & Chase 1887, p. 330, as Pleurosigma wormleyi: Cook, 

 Chicago — Lake Michigan. 



MASTOGLOIA Thwaites, 1856 



M. SMiTHii Thw. Boyer, loc. cit., p. 332 (1927). 



Thomas & Chase 1887, p. 329: Cook, Chicago— Lake Michi- 

 gan. 



