4(37 



Nordstedtia Borai, 208 



Nostoc Vauchcr, II, 15, 16, 17, 23, 24, 25, 20, 

 28, 31, 43, 44, 422 



N. aiitnrcticum W. & G. S. West, 17 (fig. 11 D 

 and E) 



N. carneum Ag., 17 (fig. 11 C) 



N. cceruleum Lyngb., 43 (fig. 31 C) 



N. commune Vaucher, 19, 422 



N. Linckia Bornet, 43 (fig. 31 A and B) 



N. microscopicum Carm., 19 



N. minutissimum Kiitz., 447 

 Nostocaceae, 43 

 Nostochopsis Wood, 20, 25 



N. Goetzei Schmidlo, 17 (fig. 11 A and B) 

 Nylandera Harlot, 309 



Occurrence and distribution of Freshwater 



Alga>, 418-448 

 Ochlochxtc Thwaites, 298, 299 



0. ferox Huber, 300 (fig. 193 A-C) 

 (Edocladium Stahl, 385, 399 



(E. protonema Stahl, 398 (fig. 253), 399 

 (Edogoniacese, 399 

 CEdogoniales, 385-400 



(Edogonium Link, 12(i. 129, 133, 138, 139, 140, 

 143, 214, 228, 385, 386, 387, 388, 391, 

 392. 393, 394, 395, 397, 399, 429, 431, 

 443 



(E. AMstrandii Wittr., 394 (fig. 248 D) 

 (E. angustissimum W. & G. S. West, 399 

 (E. Borisianum (Le Cl.) Wittr., 387 (fig. 241), 



392, 395 (fig. 250.4) 

 (E. Boscii (Le Cl.) Wittr., 129 (fig. 89.4), 



393 (fig. 247 F and G) 



(E. Braunii Kiitz,, 395 (fig. 250 E) 



(E. ciliatum (Mass.) Pringsh., 386 



(E. concatenatum (Mass.) Wittr., 389 (fig. 



243), 395 (fig. 250 C and D) 

 (E. crassiusculum Wittr. var. idioandro- 



sporum Nordst. & Wittr., 395 (fie;. 250 B) 

 (E. fabulosum Him, 399 

 (E. fonlicola A. Br., 390, 391 (fig. 245 B-H), 



307 



(E. gigantcum Kiitz., 386 (fig. 240 D) 

 (E. Hirnii Gutw., 129 (fig. 89 B) 

 (E. Howardii G. S. West, 392 (fig. 246 A 



and B) 



(E. inconspicuum Him, 392 (fig. 246 G and D) 

 (E. Itzigsohnii De Bary var. minor W. West, 



394 (fig. 248 C) 



(E. Landsboroughii (Hass.) Wittr., 393 (fig. 



247 C-E) 

 (E. lauiumniarum Wittr., 392, 394 (fig. 249 C 



and D) 



(E. obsoletum Wittr., 394 (fig. 248 .4) 

 (E. pluviale Nordst., 389, 397 (fig. 252.4 



and B) 



(E. rivulare (Le Cl.) A. Br., 391 (fig. 245.4} 

 (E. rufescens Wittr., 394 (fig. 249 A and B) 



- var. Lundellii (Wittr.) Him, 392 (fig. 



246 E-H) 



(E. Virceburgense Him, 392 (fig. 246 /) 

 (E. zig-zag Cleve var. robustum W. & G. S. 



West, 394 (fig. 248 B) 

 Oil (in Myxophyceae), 14; (in Peridmiete), 68; 



(in Diatoms), 96; of Green Algae, 132; 



in Ulothrix, 287 



Oligochsetophora G. S. West, 207, 208 



O. simplex G. S. West, 208 (fig. 136 E-I) 

 OLIVE, 2, 5, 9 

 OLTMANNS, 119, 150, 162, 192, 241, 248, 251, 



290, 315, 317, 328, 331 

 Oncobyrsa Ag., 33 

 ONDERDONK, 101 



Onychonema Wallich, 355, 359, 377, 381 

 0. compactum W. & G. S. West, 361 (fig. 



225^4 and B) 

 0. leeve Nordst., 361 (fig. 225 C-F) 



- var. latum W. & G. S. West, 361 (fig. 

 2256?) 



0. uncinatum Wallich, 361 (fig. 225 //) 

 Oocardium Nag., 356, 381 



O. stratum Nag., 424 

 Oocystese, 197-198 

 Oocystis Nag.. 40, 195, 197, 198. 200. 432, 440, 



452 



O. crassa Wittr., 195 (fig. 121 G and D) 

 O. elliptica W. West, 195 (fig. 121 G) 

 0. ylceocystiformis Borge, 197 

 O. natans (Lemm.) Wille, 197 

 O. pandurifvrmis W. & G. S. West, 195 (fig. 



121 E and F) 



O. solitaria Wittr., 195 (fig. 121 A and B), 425 

 0. submarina Lagerh., 140, 196 (fig. 122 



A-F), 198 



Oodesmus Schmidle, 407 

 Ophiocytiacea}, 409 

 Ophiocytium Nag., 403, 404, 409 410, 430, 446 



411 



0. bicuspidalum (Borge) Lemm. forma longi- 

 spina Lemm., 410 (fig. 261 H and /) 



O. cochleare (Eeichw.) A. Br., 410 (fig. 261 

 B-G) 



0. graciliceps (A. Br.) Rabenh., 410 (fig. 

 261 K) 



O. majus Nag., 410 (fig. 261 A), 430 



0. parvulum (Forty) A. Br., 430 

 Ophiothrix, 22 

 Ophrydium, 194 

 Ornithocercus Stein, 62 



Oscittaioria Vaucher, 2, 5, 10, 16, 20, 21, 22, 

 23, 25, 26, 27, 31, 33, 42 



0. acuminnta Gom., 42 (fig. 29 E) 



0. Agnrdhii Gom., 31, 434, 435 



O. decolorata G. S. West, 12, 39 



0. irrigua Kiitz., 42 (fig. 29 B) 



0. limosa Ag., 13 (fig. 9 B), 42 (fig. 29 .4) 



0. rubescens D. C., 11, 31 



0. splcndida Grey., 42 (fig. 29 D) 



O. tennis Ag., 42 (fig. 49 C) 

 Oscillatoriaceae, 42; movements, 20-22 

 OSTENFELD, 111, 436, 440 

 OSTENFELD & WESENBERG-LtTND, 440 

 Ostreobiurn Born. & Flah., 243 



0. Que.ke.tii Born. & Flah., 243 

 OTT, 120 



Ourococcus Grobety, 204 

 Ourococcus insignia Hassall, 58 

 OVERTON, 178, 181, 350 

 Ovulites, 239 

 Oxytoxum Stein, 58, 61, 68 



Pachysphsera pelagica Ostenf., 216 



