FRESU-WATER ALQJE OF THE UNITED STATES. 41 



ing note: "In bottom of shallow, slowly running streams, adhering to ground or 

 fallen leaves, &c., gelatinous green." The specimens agree well with the descrip- 

 tion of the European form, except that I have never seen the joints globose or ellip- 

 tical, but always cylindrical, as they are said to be sometimes in the typical speci- 

 mens. The color of the spores also is not " fuscous," but that probably depends 

 upon their not being fully mature. 



Fig. 7, pi. 2, represents the spore of this species with the neighboring hetero- 

 cyst, magnified 750 diameters. 



C. COmatllin, Wood (sp. nov.) 



C. terrestre, stratum gelatiuosum serugineum interduni brunneo tinctum, formans; triehomati- 

 bus flexuosis, intricatis, baud spiralibus, sequalibus ; articulis breve cylindraceis, diametro 

 aequalibus ad plus dupio lougioribus, plerumque sejunctis, pallide aerugineis, obscure granu- 

 latis ; ccllulis terminalibus subglobosis ; sporis oblongo-eylindricis, diametro fere duplo lougi- 

 oribus, granulatis, luteo-brunitcis ; membrana crassa, distincte granulata. 



Diam — Spor. transv. -r^Sijij" = .00042". Long. j^ViJcj" = .00092". Artie. .0001". 



Hab. — In terra uda ; Niagara, Canada. 



Growing on tbe ground, forming a gelatinous stratum of an seruginous color, sometimes tinged 

 on edges with brown; filaments fle.xuous, equal, intricate, not spiral; joints shortly cylin- 

 drical, equal to or more than twice as long as the diameter, mostly separated, pale ffiruginons, 

 obscurely granulate, terminal cells subglobosc ; spores oblong-cylindrical, about twice aa 

 long as broad, granulate, yellowish-brown ; membrane thick, distinctly granulate. 



Remarlis. — I found this Ci/Iindros^yenmitn growing upon the ground in the 

 marshes which border the Niagara River just above the Canadian Falls. It formed 

 a bright, a?ruginous, gelatinous, but firmish, almost membranous, stratum. 



The filaments are often quite long, and are composed of sliort, cylindrical cells, 

 mostly placed rather far apart. The terminal cells are remarkable for being abun- 

 dantly provided with long, flexible, hair-like processes, upon the cuds of which are 

 minute lobular bodies (cells?). These appendages are so minute as to make it diffi- 

 cult to determine their structure, and although I have studied them with a ^'^th 

 immersion lens, giving a power of nearly 2500 diameters, there arc some points 

 about them still inidetermincd. I do not know whctlier they or the little globules 

 are hollow or not. I do feel pretty certain, however, that the little globules are 

 distinct bodies, and that they finally drop off, leaving the naked hair behind. Is 

 it possible that they have any sexual significance ? The spore-wall is thick, and 

 under a high power is seen to be distinctly granulate. The granules are of course 

 small, but in the perfected spore can plainly be seen with an eighth objective pro- 

 jecting out from the margin. 



Fig. 8, pi. 2, represents the spore-end of a filament, magnified 1375 diameters. 



Genus DOLICHOSPEllMUM, Thwaites. 



Spora; cllipticae, oblongre vel cylindraccae, inter cellulas vegetativas ortse, ssepe in seriebus con- 

 nexse, a cellulis perdurantibus disjunctae. 



Spores elliptical, oblong, or cylindrical, occurring amid.st the vegetative cells, often connected in 

 series, separated from the hetcrocysts. 



6 April, 1872. 



