94 A CATALOG OF ILLINOIS ALGAE 



O, OBLONGUM var. MAjus Nordst. Tiffany, loc. cit., f. 344 (1937), 



Transeau: Coles, Dorans, Lerna — (Apr., May). 

 O. OBOVIFORME Wittr. Tiffany, loc. cit., p. 38. pi. 13. f. 168, 169 (1937). 



Transeau: Coles, Lerna — pond (Apr.). 

 O. OBSOLETUM Wittr. Tiffany, loc. cit., p. 30. pi. 9. f. 117 (1937). 



Johnson & Atwell 1890, p. 19: Cook, Evanston— "Big Woods" 



(Apr.). 

 O. OBTRUNCATUM Wittr. Tiffany, loc. cit., p. 27. pi. 25. f. 408 (1937). 



Transeau 1913B, p. 84; 1913C, p. 34; 1916, p. 124: Coles, 



Charleston— pond (Oct.). Tiffany 1930, p. 155; 1937, p. 72; 



1939, p. 91. 

 O. occiDENTALE (Hirn) Tiff. Tiffany, loc. cit., p. 41. pi. 16. f. 211-213 

 (1937). 



Transeau: Clark, Casey — pond (Apr., May). Coles, Lerna — pond 



(May). 

 O. OUCHITANUM Taft. Tiffany, loc. cit., p. 76. pi. 20. f. 303, 304 (1937). 



Tiffany 1939, p. 91. 

 O. PALUDOSUM (Hass.) Wittr. Tiffany, loc. cit., p. 41. pi. 15. f. 208 

 (1937). 



Transeau 1913B, p. 84: Clay — pond (May). Coles, Lerna— ponds 



(Apr., May). Tiffany 1930, p. 90; 1937, p. 41; 1939, p. 91. 

 O. PALUDOSUM var. parvisporum Hirn. Tiffany, loc. cit., f. 209 (1937). 



Transeau 1913B, p. 84; Collins 1918, p. 63: Coles, Charleston, 



Dorans — ponds, pools and ditches (Apr., May, Nov.). Britton: 



Cook, Glenview — swamp and small pond about 1| miles W., 



May 12, 1938, #58; Northbrook- — small pond at Somme Forest 



Preserve, May 15, 1938, #68. Transeau: Douglas, Arthur — pool 



and pond (May). Lawrence, Lawrenceville — gravel pit (Apr.). 



Montgomery, Coffeen— pond (May). Tiffany 1930, p. 90; 1937, 



p. 41. 

 O. paucocostatum Trans. Tiffany, loc. cit., p. 46. pi. 19. f. 263, 264 

 (1937). 



Transeau 1914, p. 300; Collins 1918, p. 66: Clark, Casey— pond 



(July). Coles, Charleston— pond (Sept., Oct.). Tiffany 1930, p. 



98; 1937, p. 46; 1939, p. 91. 

 O. PAULENSE Nordst. & Hirn. Tiffany, loc. cit., p. 40. pi. 15. f. 197, 198 

 (1937). 



Britton : Cook, Northbrook— ponds and swamp at Somme Forest 



Preserve, May 15, 1938, #65, 66. 

 O. PERFECTUM (Hirn) Tiff. Tiffany, loc. cit., p. 62. pi. 35. f. 547, 548 

 (1937). 



Transeau: Coles, Charleston — pond (Mar.). 

 O. PISANUM Wittr. Tiffany, loc. cit., p. 50. pi. 21. f. 323, 324 (1937). 



Transeau: Montgomery, Coffeen — pond (May). Tiffany 1930, 



p. 109; 1937, p. 50; 1939, p. 91. 



