1922] 



PFEIFFER MONOGRAPH OF THE ISOETACEAE 189 



Krebssee, near Heringsdorf, I. of Usedom, 9 September, 

 1902, without collector (U. S. Nat. Herb.); "Feldsee bei 

 Freiburg," 7 July, 1864, Reess (U. S. Nat. Herb.) ; 

 Titisee near Freiburg, 1866, Magnus (U. S. Nat. Herb.); 

 Titisee, Schwarzwald, 1ST-, Reinsch (U. S. Nat. Herb.); 

 Feldbergsee, Schwarzwald, 30 June, 1808, Zickendrath 

 (N. Y. Bot. Gard. Herb.) ; on stony bottom of Feldsee, 

 Feldberg, Schwarzwald, 17 July, 1834, Meisner (N. Y. 

 Bot. Gard. Herb.); Einf elder See, Lauenburg, Schles- 

 wig-Holstein, Nolte 1601 (N. Y. Bot. Gard. Herb.); Titisee, 

 1000 m., September, 1885, Christ (N. Y. Bot. Gard. Herb.) ; 

 20-50 cm. below water surface, stony substratum, in Stein- 

 see near Kirchseeon, upper Bavaria, July, 1900-01, and July 

 & August, 1902, Hepp 599 (Gray Herb.); in lake, Gardsee, 

 Ratzeburg, September, 1864, Reinke (Gray Herb.); Grosser 

 Teich, Riesengebirge, Silesia, July, 1866, Milde (Gray 

 Herb.) ; Grosser Teich, Riesengebirge, 31 July, 1874, Buck- 

 enau (Gray Herb.) ; Wiggoda in Moritzsee, West Prussia, 

 10 May, 1885, Lutzow (Gray Herb.); Gr. Ottalsiner See, 

 West Prussia, 10 August, 1885, Lutzow (Gray Herb.) ; 

 Schluchsee in Black Forest, September, 1887, without col- 

 lector (Gray Herb.) ; Riesengebirge, 24 August, 1884, 

 Hieronymus (Mo. Bot;> Gard. Herb.); near Danzig, W. 

 Prussia, 1854, Klebsman (Mo. Bot. Gard. Herb.) ; millpond, 

 "Lohmiille", near Lockstedter Lager, Holstein, August, 1886, 

 without collector (Mo. Bot. Gard. Herb.). 



Bohemia: Bistritzer See, near Eisenstein, Celakovsky 1503 (U. 

 S. Nat. Herb, and Gray Herb.). 



Austria: "Grosser Teich," Sudetic Mts., Milde (Mo. Bot. Gard. 

 Herb.). 



Finland: Northern Lavonia, Kvopio, 26 July, 1901, Budden (U. 

 S. Nat. Herb.) ; region of Abo "par. Lojo" in lacu Hormasjo, 

 6 September, 1893, Boldt 17 (Mo. Bot. Gard. Herb.) ; same 

 station, 27 August, 1909, Boldt 418 (Mo. Bot. Gard. Herb.). 



Russia: St. Petersburg, "Hellgriindiger See in Lewaschweo," 

 2-19 August, 1898, Poring (U. S. Nat. Herb.). 



52. 1. occidental Hend. Bull. Torr. Bot. Club 27: 358. 1900. 

 /. lacustris var. paupercula Engelm. Trans. St. Louis Acad. 

 Sci. 4: 377. 1882. 



