FRESH-WATER ALGJil OF THE UNITED STATES. 71 



Hah. — In rupibus irroratis inter muscis minutis. Mount Tahawus {vulgO Mount Marcy),' alt. 

 5000 feet. 



Forming a blackish, widely expanded, tomentose turfy covering to rocks ; filament with scat- 

 tered branches ; branches mostly single, often elongate and clavate ; cells uniseriate, about 

 equal, or shorter than long, sometimes subglobose, often subquadrate ; in advanced age often 

 strongly compressed and transversely oblong from mutual pressure, yellowish, or sometimes, 

 when young, greenish ; the apical cells coalescent into an irregularly cylindrical mass ; hete- 

 roeysts wanting ; sheaths yellowish-brown ; at maturity more or less subopaque, and distinctly 

 ' lamellate ; in youth more or less transparent, and sometimes colorless 



BemarJcs. — Near the top of Mount Tahawus, in the Adirondack Mountains, 

 there is, at an altitude of about five thousand feet, a steep slope of bare rock, 

 the bed of an old landslide, over portions of vphich water is continually drip- 

 ping. In such places the plant under consideration flourishes, forming with 

 some very minute mosses a blackish, turfy coating to the rock of many feet, 

 or even, yards, in extent. The specimens agree well with the descriptions of the 

 European plant, which also grows at about the same altitude as the American. 

 They have, however, one peculiarity not noted in description of the European 

 form, namely, that oftentimes the sheath of a branch widens out until it is actually 

 much larger than the main filament. The color of the cells in the European form 

 is said to be aeruginous ; but I conceive this depends somewhat upon the age of 

 the specimens and is scarcely of primary value. . The only other diff'erence worth 

 noticing is that my measurements exceed somewhat those given of the European 

 plant. I do not think, however, there is any good ground for separating the forms 

 as distinct species. 



The finding of an Alpine plant growing on a mountain half way across the world 

 from its first discovered home, at practically the same altitude, is a matter worth 

 noting as a fact in Botanical Geography. 



S. negrlectns, Wood. 



S. immersus ; trichomatibus subsolitariis, longis usque ad lineas quatuor, cylindricis, ramossis- 

 simis ; ramulis singulis ; cytioplasmate interdum aerugineo, plerumque aureo-brunneo; cellulis 

 uniseriatis rarissime biseriatis, subglobosis, interdum sejunctis sed plerumque arete connectis 

 et moniliformibus, modo confluentibus, baud distincte pachydermaticis ; cellulis terminalibus 

 elongato-cylindricis, ssepe nonnihil oscilatorium modo articulatis ; cellulis interstitialibus nullis ; 

 vaginis interdum brunneis, plerumque coloris expertibus. 



Biam. — ^Trichom. cum vag. 5}/' =.001T" ; sine vag. y^Vtr" = -001". 



Syn. — S. neglectus, Wood, Prodromus, Proc. Amer. Philos. Soc, 1869, p. 133. 



Hab. — In stagnis. New Jersey. 



S. immersed, subsolitary, attaining a length of 4 lines, cylindrical, very much branched ; branches 

 single ; cytioplasm a;ruginous, mostly yellowish-brown ; cells uniseriate, very rarely biseriate, 

 subglobose, sometimes separate but more frequently closely united and moniliform ; terminal 

 cell an elongated cylinder, often articulate somewhat like an oscillatoria ; interstitial cells 

 wanting ; sheaths transparent, sometimes brown, mostly colorless. 



' " Tahawus," cloud splitter. The Indian names of the American mountains ought to be retained, 

 in spite of the fact that some vulgar land surveyor has defiled the Adirondacks with the names of 

 politicians, through whose influence he hoped for patronage. 



