264 FRESH- WATER ALG.E OF THE UNITED STATES. 



s 



green, continuous or distinctly articulate, joints equal to a 

 little longer than broad ; sheaths narrow, colorless ; hetero- 

 cysts two or three (rarely more) in a series ; oblong hyaline. 



Diameter of filaments, including sheath, 8-9 yw. 



A stormy day at Budd's Lake, New Jersey, August, 1881, 

 brought large quantities of this plant into the sheltered 

 coves of the lake ; the water was literally covered with 

 what appeared to be rather large, somewhat faded green 

 peas, all perfectly spherical. The agitation of the water 

 probably tore the plants from their attachments and washed 

 them to the shore ; except for this habit of forming spherical 

 clusters, it can not be separated from the following T. 



Plate CLXXXI, figs. 1-4, individual filaments. 



TOLYPOTHRIX MUSCICOLA, Kg. 



Caespitose floccose, aeruginous or fuscous, branches freely, 

 elongate, loosely intricate ; internal filaments light aerugi- 

 nous, distinctly articulate, often apparently interrupted by 

 the turning or inclining of the disc- like cells. Sheath thin 

 and close, colorless ; heterocysts subglobose or oblong, two 

 or three in series. 



Diameter, 9-11 yu. 



Usually found in ponds, or sluggish river waters attached 

 to water mosses and other plants. 



Where this plant prevails there are in proper season, an 

 abundance of forms as illustrated Plate CLXXV, figs. 1-8, 

 evidently the young stage of development of Tolypothrix; 

 the filaments at first flagelliform, then linear, and often 

 elongated before they commence branching. Compare also 

 page 241 (Mastlgonemct). 



Plate CLXXXI, figs. 1-4, filaments of T. aegagropila, or 

 T. muscicola. 



TOLYPOTHRIX PULCHRA, Kg. 



Appears most nearly related to T. distorta, but slighter ; 

 bright, somewhat dilute, aeruginous, grows in tufts ; articu- 

 lations rather shorter than longer than the diameter ; sheath 

 thin and close, colorless or light yellow. Heterocysts 

 usually geminate. 



Diameter of filaments, 12-14 fji. 



Attached to sticks and the like in ponds. 



Syn. T. aegagropila, var. pulchra. Kg. 

 Plate CLXXX, figs. 5-7. 



