var. minor, 364; PI. 96 

 elongatum, 364, also 363 



var. major, 364; PI. 94 

 gracilipes, 364, also 362; PL 95 

 Lagerheimii, 364 

 majus, 365, also 363, 364; PI. 94 

 mucronatum, 365, also 362; PL 94 

 parvulum, 365, also 363; Pis. 94, 96 

 Ophrydium, 235 



Oscillatoria, 481, also 6, 7, 39, 478, 480, 

 492, 592 

 acutissima, 484, also 482; PL 109 

 Agardhii, 484, also 483; PL 108 

 amoena, 484, also 482, 483; PL 109 

 amphibia, 485, also 483; PL 109 

 anguina, 485, also 483; PL 108 

 angusta, 485, also 482; PL 109 

 angustissima, 485, also 482; PL 109 

 articulata, 486, also 482; PL 107 

 Bornetii, 486, also 482; PL 108 

 chalvbea, 486, also 482, 483; PL 109 

 curviceps, 487, also 482; PL 108 

 formosa, 487, also 484; PL 109 

 granulata, 487, also 483; PL 109 

 Grunowiana var. articulata. Sec 

 Oscillatoria articulata 

 Hamelii, 487, also 483; PL 109 

 lacustris, 488, also 483; PL 109 

 limnetica, 488, also 482; PL 109 

 Umosa, 489, also 482; PL 109 

 minima, 489, also 482; PL 107 

 nigra, 489, also 483, 484; PL 109 

 ornata, 489, also 482, 483 

 princeps, 489, also 482, 501, 502; PL 110 

 prolifica, 490, also 483; PL 110 

 rubescens, 490, also 482, 483, 528; PL 



107 

 sancta, 490, also 482; PL 110 



var. aequinoctialis, 491 

 splendida, 491, also 482; PL 110 

 subbrevis, 491, also 483; PL 107 

 tenuis, 491, also 483; PL 110 



var. natans, 491, also 492; PL 110 



var. tergestina, 492; PL 110 

 terebriformis, 492, also 483, 484; PL 107 

 Oscillatoriaceae, 478 

 Oxygen, 40, 44 



Palmella, 83, also 82, 573 



mucosa, 83; PL 3 

 Palmellaceae, 82 



Palmodictyon, 85, also 82, 574, 581 

 varium, 85; PL 4 

 viride, 85; PL 4 

 Pandorina, 75, also 15, 74, 572 



morum, 75; PL 1 

 Paramylon, 387 

 Pascheriella, 79 



Pediastrum, 220, also 219, 576 

 angulosum, 221 



var. araneosum. See Pediastrum 

 araneosum 

 araneosum, 221; PL 47 



var. rugulosum, 222; PL 47 

 biradiatum, 222, also 221; PL 47 



var. emarginatum fa. convexum, 222; 

 PL 47 

 Boryanum, 222, also 221; Pis. 47, 48 

 var. longicome, 222; PL 47 

 var. rugulosum. See Pediastrum 



araneosum 

 var. undulatum, 223; PL 48 

 Braunii, 223, also 221; PL 48 

 duplex, 223, also 11, 221; PL 48 

 var. brachylobum, 223 

 var. clathratum, 223; PL 48 

 var.' cohaerens, 224; PL 48 

 var. gracilimum, 224; PL 48 

 var. reticulatum, 224; PL 49 

 var. rotundatum, 224; PL 48 



var. rugulosum, 224; PL 49 

 glanduliferum, 224, also 221; PL 49 

 integrum, 225, also 221; PL 48 

 fa. glabra, 225 

 var. priva, 225; PL 48 

 var. scutum, 225; PL 49 

 Kawraiskyi, 225, also 221; PL 50 

 muticum, 225, also 221; PL 49 

 var. crenulatum, 226; PL 49 

 obtusum, 226, also 221; PL 49 

 quadricomutum. See Pediastrum obtusum 

 sculptatum, 226, also 221; PL 49 

 simplex, 227, also 220; PL 50 



var. duodenarium, 227; PL 50 

 tetras, 227, also 221, 225, 226, 576; PL 

 50 

 var. obtusata, 227 

 var. tetraodon, 227; PL 50 

 Pelogloea, 561, also 591 



bacillifera, 561, also 36, 37; PL 104 

 Peranemaceae, 387 

 Peridiniaceae, 431, also 427 

 Peridiniales, 427, also 425 

 Peridinin, 424 

 Peridinium, 431, also 590 



Borgei. See Glenodinium Borgei 

 cinctum, 432; PL 91 



var. Lemmermannii, 432 

 var. tuberosum, 433, also 432; PL 91 

 gatunense, 433, also 432; PL 90 

 inconspicuum, 433, also 432; PL 90 

 limbatum, 434, also 432; PL 91 

 pusillum, 434, also 432; PL 107 

 Willei, 434, also 432; PL 91 

 wisconsinense, 435, also 432; PL 91 

 Periphyton, 3 

 Perone, 352, also 348, 588 



dimorpha, 353; PL 95 

 Peromelia, 359, also 91, 357, 588 

 Hyalothecae, 359; PL 94 

 planctonica, 359; PL 94 

 pH, 6, 12, 16, 17. 19, 20, 22, 26, 27, 28, 



30, 32, 33, 37, 43 

 Phacotaceae, 68, 69, 73 

 Phacotus, 73, 572 

 lenticularis, 73 

 Phacus, 395, also 389, 585 



acuminatus, 396, also 395; PL 88 



var. Drezepolskii, 397; PL 88 

 alatus, 397, also 396 

 anacoelus, 397, also 396; Pis. 87, 88 

 var. undulata, 397; PL 87 

 fa. major, 398; PL 89 

 asymmetricum, 398, also 395; PL 88 

 Birgei, 398, also 396; PL 87 

 caudatus Ehr. See Phacus acuminatus 



var. Drezepolskii 

 caudatus Hueb., 398, also 396; PL 87 



var. ovalis, 398; PL 88 

 chloroplastes, 399, also 395; PI. 87 



fa. incisa, 399; PL 88 

 circulatus. See Phacus orbicularis var. 



Zmudae 

 costata, 399 



crenulata, 399, also 395; PL 88 

 curvicauda, 399, also 396; Pis. 87, 88 

 helikoides, 400, also 395; PL 87 

 hispidula, 399 



Lemmermannii, 400, also 396; PL 88 

 longicauda, 400, also 395; PL 87 

 Nordstedtii, 401, also 395; PI. 88 

 orbicularis, 401, also 396; PL 87 

 var. caudatus, 401; Pis. 87, 88 

 var. Zmudae, 401; PL 88 

 platalea. See Phacus orbicularis var. 



caudatus 

 pleuronectes, 402, also 396; PL 88 

 pseudoswirenkoi, 402, also 396; Pis. 85, 



87, 88 

 pyrum, 402, also 395; PL 88 



[973] 



