TOLYPOTHRIX. 265 



TOLYPOTHRIX BAVENELII, Wolle. 



Forms a thin stratum on exposed sand-stone and rocks ; 

 reddish brown, sheath thin and close ; articulations half as 

 long as wide, or more rarely as long as wide. Internal 

 trichome now and then interrupted by inclining cells caus- 

 ing dark transverse bands. Heterocysts single, usually 

 longer than wide, oval. 



Diameter of filaments averaes 20 ^ (15-25 



Bears a resemblance to T. distorta in size, but strikingly 

 distinct in color, if normal, and in habitat. Had fine speci- 

 mens, but only once, from Gainesville, Florida, December, 

 1877. Collected by H. W. Ravenel. 



Plate CLXXX, figs. 8, 9, 10. 



TOLYPOTHRIX RUPESTRIS, Wolle. 



Strata expanded on dripping, gelatinous, exposed rocks, 

 variously tinged with red, purple and black ; trichomes 

 much branched, loosely interwoven ; internal filaments dull 

 aeruginous, granular ; articulations as long or twice as long 

 as the diameter. Sheaths wide, yellowish, or colorless ; 

 heterocysts oblong or less frequently globose, two or three 

 in series. 



Diameter of filaments, 12-15 yw. 

 Wet rocks, Pennsylvania. 



Plate CLXXX, figs. 11, 12, 13, specimen from the Dela- 

 ware Water Gap, Pa. 



TOLYPOTHRIX FLACCIDA, Kg. 



Caespitose, aeruginous, trichomes and jpsewdto-branchlets 

 spreading, elongated, flaccid, arising from a prostrate base 

 internally pale aeruginous, distinctly articulate, joints a 

 little shorter than broad, sheaths colorless, rather broad; 

 heterocysts subglobose or oblong, two or three in series, 

 colorless, or light yellow. 



Diameter of filaments, 10-13 yw. 



Ponds, Pennsylvania. 

 Plate CLXXX, figs. 14-16, parts of three filaments. 



TOLYPOTHRIX TENUIS, Kg. Forma BRYOPHILA, Eab. 



Small caespitose tufts, on water mosses ; gelatinous, olive- 

 brown ; filaments sparsely branched ; articulations about 

 as long as broad, often indistinct ; light aeruginous or yel- 



