CLASSIFIED CATALOG OF ILLINOIS ALGAE 133 



NETRIUM Naegeli, 1849; Luetkemueller, 1902 



N. DIGITUS (Ehr.) Itzigs. & Rothe. West & West, loc. cit., p. 64. pi. 6. 



f. 14-16 (1904). 



Transeau: Clark, Casey — pond (May). Britton: McHenry, Har- 

 vard — swamp about 2 miles N.E., July 8, 1939, #436. Eddy 

 193 IB, pp. 451, 462: Pulaski, Wetaug — sink-hole ponds (Apr., 

 July, Sept., Dec). 



ROYA W. & G. S. West, 1896; Hodgetts, 1920 



R. OBTUSA (Breb.) W. & G. S. West. West & West, loc. cit., p. 107. pi. 

 10. f. 27 (1904). 



Closterium obtusum Breb. 



Johnson & Atwell 1890, p. 20, as Closterium obtusum: Cook, 



Glencoe — ( Apr . ) . 



Family: DESMIDIACEAE 



ARTHRODESMUS Ehrenberg, 1838 



A. CONVERGENS Ehr, West & West, Brit. Desmid. 4: 106. pi. 116. f- 



4-13 (1912). 



Britton: Cook, Sag Bridge — small ponds, July 13, Sept. 8, 1939, 

 #507, 997, 998; Schnells Corner— pond at Elk Grove Forest Pre- 

 serve, June 22, 1939, #327. Lake, Volo— bog at Tamarack Farm, 

 June 3, 1939, #294. 



CLOSTERIUM Nitzsch, 1817 



C. ACEROSUM (Schr.) Ehr. West & West, Brit. Desmid. 1: 146. pi. 18. 



f. 2-5 (1904). 



Kofoid 1903, p. 516; 1908, pp. 11, 60, 292, 319 (Mason). Solheim 

 & Penfound 1928, p. 88 (Champaign). Eddy 1931A, p. 486 

 (Macon, Menard); 1931B, pp. 451, 462 (Pulaski); 1934, pp. 385, 

 386, 389-391, 393, 394, 396, 399, 402, 403 (Adams, Alexander, 

 Calhoun, Champaign, Hancock, Henry, Jersey, Macon, Madi- 

 son, Mason, McHenry, Ogle, Piatt, Pike, St. Clair, Union, 

 Whiteside). Transeau (Coles). Britton (Cook). 



Adams — Mississippi River (June). Alexander — Horseshoe 

 Lake (June-Aug.). Calhoun — Mississippi River (June). Cham- 

 paign, Urbana^Ox-bow pond (May-Aug.), small stream N. of 

 (Apr.-June). Coles, Charleston— pond (Mar.). Cook, Morton 

 Grove — small reservoir, May 10, 1938, #42. Hancock — Missis- 

 sippi River (June). Henry, Colona — slough (June-Aug.). Jersey 

 — Mississippi River (June). Macon, Decatur — park pond and 

 Lake Decatur (Mar.-Dec); Harristown^ — Sangamon River 



