FRESH-WATER ALG^ 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 comatuin, Wood (sp. nov.) 



C. terrestre, stratum gelatinosum aerugineum interdum brunneo tinctum, formans; trichomati- 

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

 sequalibus ad plus duple longloribus, plerumque sejunctis, pallida aerugineis, obscure granu- 

 latis ; cellulis terminalibus subglobosis ; sporis oblongo-cylindricis, diametro fere duplo longi- 

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



Dmni.— Spor. transv. y^^^/ = .00042". Long. i^Vtt/ = -00092". Artie. .0001". 



Hah. — In terra uda ; Niagara, Canada. 



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

 on edges with brown; filaments flexuous, equal, intricate, not spiral; joints shortly cylin- 

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

 obscurely granulate, terminal cells subglobose ; spores oblong-cylindrical, about twice as 

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



Remarlcs. — I found this Gylindrospermum growing upon the ground in the 

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

 a bright, seruginous, gelatinous, but firmish, almost membranous, stratum. 



The filaments are often quite long, and are composed of short, 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 ends of which are 

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

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

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

 about them still undetermined. I do not know whether 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 DOLICHOSPEKMUM, Thwaites. 



SporEe ellipticBB, oblongse vel cylindracese, inter cellulas vegetativas ortee, ssepe in seriebus con- 

 nexae, a cellulis perdnrantibus disjunctae. 



Spores elliptical, oblong, or cylindrical, occurring amidst the vegetative cells, often connected in 

 series, separated from the heterocysts. 



6 April, 1872. 



