i K i:sn-\v A I i: K \i.i;.i: n riii-: UNITED STATES. 03 



v since I have examined some hundreds of specimens, and have only in one 

 instance detected tin in in pairs. The apices of the branches, and indeed of 

 the main filament.*, arc In -.uitifully colorless and hyaline, and not nnfrcqncntly a 

 hranch will have this hyaline sheath for a long distance. The extreme ends are 

 mostly truncate and open, and, often nrar them, the sheaths will have marked 

 swelling- ; a condition which, for want of a hetter term, I have spoken of as being 

 /,.///.. 8 'inetimes IK ar the end of the filament the diameter of the sheath will 



:<MenI\ Irssriied. The large celN ale lioth interstitial and placed at the bases 

 of the branches ; they are more or less oblong or quadrangular, sometimes being 



-h longer than broad, but in other cases several times longer. At their posi- 

 tion there i> \.ry generally a sort of globular enlargement of the filament. The 

 sheath is sometimes very obscurely lamellate. The color of the 'older filaments is 

 a dark, almost cliocolate-hrown. This is apparently the species referred to by 

 Professor Hailey as being Scytanema ocellatum of Harvey, in Silliman's Journal, vol. 

 iii. N. S., although that plant, according to Professor Uubenhorst, belongs to the 



gelllis Sn-iK.;jJii,ii. 



Fig. 1 </, pi. 7, represents a portion of a filament, magnified 280 diameters; fig. 

 1 I, a whole filament slightly magnified. 



S. diihiiim, Wo<>r> (sp. nor.) 



S. inniuTsum, in fluccis mucoso-tomcntosis olivaoco-nigris plantns aqaaticas ailliirronit, vcl in 

 strata raucoso et nonnibil tomcntoso dispositum ; trichomatibua valde clongatis et arete in- 

 trirutis, vurie curvatis, plerumque sparse pseudoramosis; pseudoramulis plenimquc singulis, 

 etplus minus distantibns et modice brcvibns, vcl intcrdum brevi&simis et abortivis et nonnihil 

 confcrtiii; trichomatibus internis sepe in pscndocellalis distinctis contends, intcrdum con- 

 timiis ct imlistincte articalatis vcl inarticulatis, plerumqne dilute ctcruleo-riridibug sed inter- 

 iluiii liete nrugineis, snbtilitcr granulatis ; vaginis arctis plerumqne modice rm.-.-is et firmix, 

 hyalinis, coloris expcrtibus; ccllulis perdnrantibus cylindricis, dianietro 2-C plo longioribus. 



Diam.Cam vag. irl^" nf "- .00025" .0004". 



''. In aqnis quictis, Cumberland County, New Jersoy. 



liiiiiicr-i(l, adhrring to water plants in olive-black tomcntosc flocculent masses, or arranged 

 in a mncous and somewhat tomcntose stratum ; trichomata very long and closely interwoven, 

 variously curved, mostly sparsely branched ; branches generally single, more or less distant, 

 and moderately short, sometimes very short, abortive, and somewhat crowded ; internal fila- 

 ment often contained in distinct cell-like apartments, sometimes continuous and indistinctly 

 articulate, or not at all articulate, finely granulate, mostly a pale bluish-green, sometimes a 

 bright ernginous color; sheath close, mostly rather thick and firm, hyaline colorless; hetcro- 

 cysts cylindrical, 2-6 times longeV than broad. 



*. 1 found this plant, September, 1869, in Shepherd's Mill Pond, near 

 1 nwich, Cumberland County, New Jersey. It formed dark, ugly, somewhat 

 slimy, tomontose flocculi adhering to, and binding together, the finely-dissected 

 es of Ranunculus aqiiatili*. The filaments are very long, slender, and sparsely 

 branched. The branches are given off at right angles, or nearly so, but arc fre- 

 quently sharply bent just above their origin. They are often, but not always. 

 rather short. The most remarkable character that the plant possesses is that in 

 many filaments there are very distinct regular partitions stretching across from 



