114 FRESH- WATER ALG^E OF THE UNITED STATES. 



STIGEOCLONIUM FASCICULAKE, Kg. 



Caespitose, two or more inches in length, bright green, 

 mucous, branching mostly opposite, dichot onions ; upper 

 part fasciculately branched ; diameter of basal cells, 12-15 ^ ; 

 length 4-8 times more (1-2, Kg.); primary branches erect 

 patent, short, close, ending with a bristle point; chloro 

 phylous contents of cells usually scattered. A marked dis- 

 tinction between the plant found here and that described by 

 Kuetzing is in the length of the articulations. Not to mul- 

 tiply species the name is retained with the correction 4-8, 

 instead of 1-2. 



In trench of rapidly running water, attached to rootlets ; 

 Northampton County, Pennsylvania. 



Plate XCIX, fig. 1, a single plant picked from a caespitose 

 cluster. 



STIGEOCLONIUM FASTIGIATUM, Kg. 



Pale green, small, much branched, fastigiate, radiately 

 disposed, mucous ; upper branches fastigiate, moniliform, 

 somewhat pinnate, close together, erect patent, apices pili- 

 ferous ; articulations vary from 1-3 diameters in length ; 

 sometimes constricted at the joints. 



Diameter of filaments 10-15 yu. 



Syn. Chaetophora fastigiata, Ralfs. 



Plate C, fig. 1, a single plant, very near the forms de- 

 scribed of this species, if not absolutely the same ; it has a 

 history worthy of note. Some of the species of Stigeodonium 

 are very closely related to species of Chaetophora, as is evi- 

 dent from personal observation. Eeferring to Plate CIII, 

 figs. 1, 2, two thalli of Chaetophora pisiformis magnified about 

 250 diameters. These show a few of the radiating filaments, 

 normally imbedded in a firm gelatinous mucus, extending 

 beyond the mucous tegument ; this figure, (1, 2, ) is such a 

 filament more fully developed, drawn with all of its branches ; 

 it is one of many which occurred in the same pool ; 

 Chaetophora also was prevalent in quantity. This observa- 

 tion may open the inquiry, "is this a normal process of 

 development ? Is the plant a Stigeodonium or a Chaetophora f 

 Or is the latter a mere condition of development of the 

 former ? 



Plate CII, figs. 1-3 and 5-8. Other forms developing 

 from Chaetophora, comp. Stigeo. Longipilm, and Stigeo. radians. 



