1897.] -Biological Studies in Mussachusetts. 577 
Occasionally observed. Achnanthes, Amphiprora, Amphora, 
Bacillaria, Cocconeis, Cocconema, Cymbella, Diadesmis, En- 
cyonema, Eunotia, Grammatophora, Himantidium, Isthmia, 
Meridion, Odontidium, Orthosira, Pinnularia, Pleurosigma, 
Schizonema, Striatella, Surirella, Tetracyclus. 
CHLOROPHYCE. 
Commonly found in large numbers. Chlorococcus, Protococcus, 
Scenedesmus. 
Occasionally found in large numbers. Coelastrum, Cosmarium, 
Palmella, Pandorina, Polyedrium, Raphidium, Staurastrum, 
Volvox. | 
Commonly found in small numbers. Closterium, Conferva, 
Desmidium, Euastrum,Eudorina, Gonium, Micrasterias,Ophio- 
cytium, Pediastrum, Sphaerozosma, Staurogenia, Tetraspora, 
Ulothrix, Xanthidium. 
Occasionally observed. Arthrodesmus, Bambusina, Botryo- 
coccus, Characium, Chaetophora, Cladophora, Dactylococcus, 
Dictyosphaerium, Dimorphococcus, Draparnaldia, Gloeocystis, 
Hyalotheca, Mesocarpus, Nephrocytium, Penium, Selenastrum, 
Sorastrum, Spirogyra, Stigeoclonium, Tetmemorus, Zygnema. 
CYANOPHYCEEH 
Commonly found in large numbers. Anabaena, Clathrocystis, 
Coelosphaerum, Microcysti 
Occasionally found in targe numbers. . Aphanizomenon, Chro- 
öcoccus, Oscillaria. 
Commonly found in small numbers. Aphanocapsa. 
Occasionally observed. Gloeocapsa, Lyngbya, Merismopedia, 
Microcoleus, Nostoc, Rivularia, Sirosiphon, Tetrapedia. 
FUNGI. 
Commonly found in large numbers. Crenothrix. 
Occasionally found in large numbers. Cladothrix. 
Commonly found in small numbers. Beggiatoa, Leptothrix, 
Moulds. 
Occasionally observed. Achlya, Leptomitus, Saprolegnia, Sar- 
cina, Spirillum. 
RHIZOPODA. 
Commonly found in small numbers. Actinophrys, Amoeba. 
DS st ht observed. Arcella, Cyphodera, Difflugia, Eugly- 
a. 
INFUSORIA. 
Commonly found in large numbers. Cryptomonas, Dinobryon, 
Peridinium, Synura, Uroglena. 
