Raciborski, 398 

 Segretii, 402, also 395 



var. ovum, 403; PI. 88 

 setosa var. crenata, 399 

 Spirogyra, 403, also 395 



var. maxima, 403; PI. 87 

 suecicus, 403, also 395; PI. 88 

 Swirenkoi, 404, also 396, 402; PI. 88 

 tortus, 404, also 395, 400; PI. 88 

 triqueter, 404, also 396; PI. 107 

 undulatus. See Phacus anacoelus var. 

 undulata 

 Phaeococcus planctonicus. See Chrysocapsa 



planctonica 

 Phaeophyta, 2 

 Phaeothamniaceae, 386 

 Phaeothamnion, 386, also 589 



confervicola, 386; Pis. 96, 99 

 Phormidium, 492, also 6, 7, 479, 482, 506, 

 593 

 ambiguum, 493; PI. Ill 

 autumnale, 493; PI. 107 

 Cerium, 494, also 493 

 favosum, 494, also 493; PI. Ill 

 incrustatum, 494, also 493 

 inundatum, 494, also 493; Pis. 107, 111 

 lucidum, 495, also 493 

 minnesotense, 495, also 493 

 mucicola, 495, also 37, 493; PI. Ill 

 Retzii, 495, also 493; PI. Ill 

 Setchellianum, 496, also 493 

 subfuscum, 496, also 493; PI. 107 

 tenue, 496, also 493; PI. Ill 

 uncinatum, 496, also 493; PI. 107 

 Phosphorus, 15, 16, 18, 22, 26, 27, 41, 49 

 Photosynthesis, 40 

 Phycochrysin, 369 

 Phycocyanin, 443 

 Phyla. See Divisions 

 Phyllosiphon, 289, also 584 



Arisari, 289; PI. 69 

 Phyllosiphonaceae, 288 

 Phylogenetic relationships, 1 

 Physiography, 5 

 Phytomorula, 229 



regularis, 229 

 Phytoplankton. See Plankton 

 Pithophora, 139, also 135, 541, 584 

 Mooreana, 140; PL 22 

 oedogonia, 140; PI. 22 

 varia, 140; PI. 24 

 Plankton, vii, 2, 19, 22, 24, 34, 39, 40, 44, 



46 

 Planktosphaeria, 239, also 83, 233, 234, 574, 

 577 

 gelatinosa, 240, also 83; PI. 53 

 Platydorina, 74, also 572 

 Plectonema, 539, also 532, 533, 593 

 cameum, 539 



nostocorum, 539, also 561; PI. 126 

 notatTim, 540, also 539; PI. 126 

 purpureum, 540, also 539; PI. 126 

 roseolum. See Plectonema cameum 

 tenue, 540, also 539; PI. 126 

 Wollei, 540, also 501, 539; PI. 127 

 Pleodorina, 76, also 73, 74, 572 

 califomica, 77; PI. 2 

 illinoisensis, 77; PI. 2 

 ^Pleurocapsa, 590 

 Pleurochloridaceae, 348 

 Pleurococcus. See Protococcus 

 Pleurodiscus, 296 

 Pleurogaster, 353, also 349, 587 

 lunaris, 353; PI. 95 

 oocystoides, 353; PI. 95 

 Polyblepharidaceae, 68 

 Polycystis, 455, 592 

 Polyedriopsis, 271, also 235, 578 

 quadrispina 578 

 spinulosa, 272; PI. 62 



Porphyridaceae, 563 

 Porphyridium, 563, also 586 



cruentum, 564; PL 136 

 Potamogeton, 531, 560 

 Preservatives, ix 



Production in lakes, 23, 34, 35, 37, 42 

 Protococcaceae, 126 

 Protococcus, 126, also 112, 575, 578, 580 



viridis, 127; PL 10 

 Protoderma, 123, also 114, 583 



viride, 123; Pis. 9, 14 

 Pseudotetraspora, 92 

 Pseudulvella, 123, 114, 583 



americana, 124; PL 15 

 Pteromonas, 73, 572 



angulosa, 73 

 Pyramimonas, 68, also 572 



tetrarhyncus, 68; PL 1 

 Pyrrhophyta, 423, also 1, 2, 421 



Quadrigula, 259, also 234, 282, 575 

 Chodatii, 260; PL 59 

 closterioides, 260; PL 58 

 lacustris, 260; PL 59 

 Raciborskia, 439, also 438, 589 



bicomis, 440; PL 93 

 Radiofilum, 102, also 94, 582 



apiculatus. Sec Radiofilum conjunctivum 

 conjunctivum, 103, also 104; PL 7 

 flavescens, 103; PL 7 

 irregulare, 104, also 103; PL 7 

 Rhabdoderma, 462, also 445, 591 

 Gorskii, 463, also 462; PL 103 

 irregulare, 463, also 462; PL 103 

 hneare, 463, also 462; PL 103 

 sigmoidea, 462 



fa. minor, 463; PL 103 

 Rhizochloridales, 344, also 343 

 Rhizochrysidales, 380, also 369 

 Rhizochrysidaceae, 381 

 Rhizochrysis, 382, also 381, 589 



hmnetica, 382; PL 98 

 Rhizoclonium, 141, also 123, 135, 137, 138, 

 498, 500, 503, 540, 554, 581, 584 

 crassipelitum, 141; PL 23 



var. robustum, 141 

 fontanum, 142, also 141; PL 23 

 hieroglyphicum, 142, also 141; PL 23 

 var. Hosfordii, 142 

 var. macromeres, 142 

 Hookeri, 143, also 141; PL 23 

 Rhizolekane, 344 

 Rhodophyceae, 562 

 Rhodophyta, 562, also 2 

 Ricciocarpus, 521, 525 

 Rivularia, 556, also 550, 557, 560, 593 

 haematites, 556; PL 131 

 minutula, 556; PL 136 

 Rivulariaceae, 550, also 478, 509 

 Sacconema, 560, also 550, 593 



rupestre, 560; PL 136 

 Scenedesmaceae, 272, also 211 

 Scenedesmus, 273, also 212, 252, 272, 576, 

 578, 580 

 abundans, 274; PL 61 



var. asymmetrica, 274; PL 61 

 var. brevicauda, 274; Pis. 61, 62 

 var. longicauda, 274; PL 62 

 var. spicatus, 274 

 acuminatus, 275, also 273; PL 62 

 var. minor, 275 

 var. tetradesmoides, 275 

 acutiformis, 275, also 273; PL 62 

 arcuatus, 275, also 273; PL 62 

 var. capitatus, 275; PL 62 

 var. platvdjsca, 275; PL 62 

 armatus, 276, also 274; PL 62 

 var. Chodatii, 276 

 var. major, 276; Pis. 62, 63 

 var. subalternans, 276 



[974] 



