OSOILLARIA. 313 



bent ; cells >, or 2 as long as broad ; cell contents bright 

 aeruginons. 



Diameter of filaments, 4.5-5 /*. 



Plate CCVII, fig. 8, filaments from an extended stratum 

 on a shaded deposit of mud after an inundation ; Buffalo, 

 New York. 



OSCILLARIA TENUIS, Ag. 



Forming a bright green or aeruginous or with age 

 brownish stratum, short or elongate, radiating ; filaments 

 straight, rather rigid, more or less endowed with active 

 motion ; articulations usually distinct, half as long as broad 

 or before division twice this length ; apex slightly atten- 

 uated, obtuse, curved or straight ; cell contents light or 

 darker aeruginous, finely granular. 



Diameter of filaments, 5. 5-6. 5 /v. 



Syn. Oscillaria viridis, Kg.; 0. contexta, Garni. ; Oscillator ia 

 tennis, Hass. 



Babenhorst quotes nine varieties of this species, depend- 

 ing mostly on color of stratum, habitat, length and diameter 

 of cells, but all comprehended in the diagnosis above. 



Dripping mossy rocks, pools, margins of ponds or free 

 swimming. 



Plate CCVI, fig. 14, sample of filaments which make up 

 the stratum. 



OSCILLARIA CORTIANA, (Pollini) Kg. 



Forming dark aeruginous extended, floating strata on hot 

 water, 110-120 Fahrenheit. Dries with a bright luster. 

 Filaments straight, fragile, apices slightly attenuated, obtuse ; 

 articulations equal or subequal ; three to five end joints 

 somewhat curved ; cell contents light aeruginous, granular. 



Diameter of filaments, 6-7 /*. 



Plate CCVI, fig. 15, from specimens found in quantity 

 floating on hot waste-water at a large steam mill, near Beth- 

 lehem, Pa. 



OSCILLARIA LIMOSA, Ag. 



Affects limous grounds and forms an extended, thin, 

 mucilaginous, radiating green stratum ; filaments rigid, 

 straight, actively oscillating, aeruginous or with age olive 

 or brownish ; articulations usually as long as wide, but later 

 only half as long; apex obtuse, straight or curved, cell 



