FRESH WATER ALQJi OF THE UNITED STATES. 51 



From! .-mull, alimt tin- cirr "f a small pen, irregularly sulijrlolmse, soft, gelatinous, light green; 

 i!.- >;rin-rull\ -truijchti.sli, (turilv ili.-tiuriU . |>urily indiMiiirily articulate; abeaths in the 

 tiUim-iit i. ni | T |>iil>lc ; in tin- \..uii(f tiluuienU rather large in the upper portion ; 

 tiuli|(liil>M>r ur u'lobu.sc or dlijilic, iwic-o tut large as the filament, gout-rally siugle 

 but souii-tiuica bi or tri-acriiitc. 



Remarks. I found this species growing attached to tin- little leaves of various 

 minute rryptognmic and plMBMngMnk water-plants, in a small bog, near the 

 mouth of Carp Hiver, in Northern Michigan. Tlie frond is somewhat translucent, 

 with a slightly greenish tint, and has a soft, gelatinous consistency. The matured 

 triclmma or filaments are more or less radiating, very long, generally nearly straight 

 and parallel. Their joints or articles are long, mostly not very distinctly separated, 

 and often an- entirely wanting. The sheaths are entirely lost, no traces of them 

 being perceptible. They seem to be altogether melted down into the homoge- 

 neous jelly, in which the filaments are imbedded. The basal cell is large, mostly 

 globular, and very prominent. On the edges of the frond may frequently be seen 

 Miiall, evidently immature filaments, which have no distinct basal cell. Around 

 the basal portion of these \onng trichoma there is a well-marked close sheath, 

 which near tlie ape\ is wanting. In their immature filaments the joints arc mostly 

 very short, rather distinctly separated, almost globular. 



Fig. 5, pi. 4. 



Genus MASTIGOVEMA, SCHWABE. 



Trirhonintaarticulata, sursutn flagclliformia TC! subulata, simplicia vel pseodoramosa (nonnonqnam 

 fasciculutim ]>s. ud.iramosa), procumbentia vcl erecta, in Uiallo indistincto cespitoso-aggregata ; 

 vagina arete et homogcnes vel ample et plus minus distincte lamclluse, apice plerumque ujit-rtw, 

 ititcnlum laciuiaUe. 



Filaments articulate, superiorly flagelliform or subulate, simple, or falsely branched, sometimes 

 fasciculatrlj so, procumbent or erect, cwspitoscly aggregated into a sort of thallus ; sheaths close 

 and honio^rncDus or ample, and more or less distinctly lamellate, the apex for the most part open, 

 laciuiate. 



HI. fertile, WOOD, (sp. nov.) 



M. cespitosnm, cum algis altcris intermiztnm; trichomatibns simplicibnn, elongatis, flexuofto- 

 1-urvatis, apice truncatis; trichomatibus internis viridibus, soepe interrupt is, iuterdum dis- 

 tincte articulatis iuterdum inarticulatis ; articulis diametro 3-5 plo longioribus ; vaginis modico 

 arctis, firmis, achrois, crassis, coloris expertibus, apice truncatis et apertis ; nporis cylindricis, 

 Rparsis, in filamcnto nnico stepe plnribuR, in cellnlis inclnsis; cellnlis perdurantibus globosis, 

 iuterdum comprcssis trichomatis diametro fere eeqnalibus. 



^Xam.^-Filam. 5,^" - -00033" ; spor. ,^" .000166". 



Hob. In stagnis. Alleghany Mountains, Centre County, Pennsylvania. 



Cespitose, intermixed with other algae; filaments simple, elongate, flcxuonsly curved, trim- 

 rate at the, apex ; internal filament green, often interrupted, sometimes articulated, some- 

 times not articulate ; joints 2-3 times longer than their diameter ; sheath moderately close, 

 thick, firm, transparent, and colorless, truncate and open at the apex ; spores cylindrical, 

 scattered, each contained in a cell, frequently several in a filament ; hetcrocysts globose, 

 sometimes compressed, about equal in diameter to the filament. 



