396 
Chodatella citriformis Snow. 
Rhaphidium, 5 spec. 
Silenastrum, 3 spec. 
Dactylococcus infusionum Näg. 
Stichococcus bacillaris Näg. 
Pleurococcus, 2 spec. 
Chlorella, 2 spec. 
Botrydiopsis enensis Snow. 
Chlorosphaera, 2 spec. | 
Scotinosphaera paradoxa Klebs. 
Conjugatae. 
Hyalotheca dissiliens Breh. 
Onychonema laeve Nordst. 
Sphaerozosma filiforme Rabh. 
Closterium, 4 spec. 
Closterium pronum Breb. (and var.). 
Pleurotaenium trabecula Näg. 
Cosmarium, ıı spec. 
Euastrum, 2 spec. 
Staurastrum, 5 spec. 
Bacillariaceae. 
Navicula limosa Kg. 
Amphiprora ornata Bail. 
Cymbella, 2 spec. 
Encyonema prostratum Ralfs. 
Cocconema, 2 spec. 
Gomphonema, 3 spec. 
The 
floceulosa, Synedra pulchella, S. acus var. ee. Fragilaria 
Part IV. 
Chapter 2. 
| Nitzchia sigmoidea Sm. 
Campylodiscus cribrosus Sm. 
Cymatopleura solea Breb. 
Surirella, 3 spec. 
Synedra, 2 spec. 
Fragilaria, 2 spec. 
Asterionella formosa Hassal. 
Tabellaria, 2 spec. 
Melosira, 
Orthosira orichalcea Sm. 
Cyclotella, 3 spec. 
Stephanodiscus Niagarae Ehr. 
Schizophyceae. 
Rivularia radians Thur. (and var.). 
Mastigonema aerugineum Kirch. 
Aphanizomenon flos-aquae Ralfs. 
Anabaena flos-aquae Breb. 
Plectonema mirabile Thur. 
Oscillatoria, 6 spec. 
Lyngbya Wallei Farlow. 
Microcoleus anguiformis Haw. 
Merismopedia, 4 spec. 
Coleosphaerium roseum Snow. 
Clathrocystis, 2 spec. 
Gomphosphaeria aponina Kg. 
Polycystis ichthyoblabe Kg. 
Gloeocapsa fenestralis Kg. 
Chroococcus, 3 spec. 
lankton of such lakes as Winnebago, Green, Eagle varies from season to season. 
Clathrocystis, and allied forms, Oscillaria are pecalar to shallow lakes, 
Gloeotricha, although & 
. Anabaena i ordinary lo 
e Winne Ba Aster jene gracillima, Cyelotella 
rella, ee Nassula form elements of the lake diatom Aoras 
‚ Stephanodiscus, Navieula, Suri- 
ankton of western Lake Erie includes species of Merkisapkdie; Pediastrum, Sphaero- 
zyga, en and many diatoms with occasional Desmidieae 
All other Wasttached species growing in quiet places Boa a second association (Lemn& 
Fr Utricularia vulgaris, Ceratophyllum demersum, Lemna trisulca, L. minor, 
Spirodela Wolffia columbiana and with them masses of Disssuipee; Spirogyra, Hydro- 
dietyon, Öscillaria and L ya. Mieroscopic epiphytie bundant here. This 
association is found well developed in western Lake Eri plants forming a third association 
occupy by far the largest place in aquatie vegetation. The A, Chara fragilis, C. coronate, 
Associatio 
ı) MArsH, C. DwicHT: The Plankton of Lake Winnebago and Green Lake. Wisconsin Geo- 
logical and Natural History Survey Bulletin XII. October 1903. 
