FRESH-WATER ALG^ OF THE UNITED STATES. 205 



iGodwinsville, New Jersey." As dried, the plant is in extended, gray, felt-like 

 Imasses. The walls of the articles as seen with the microscope are thick and 

 irregular, and the joints themselves are also very irregular, the end ones being often 

 swollen and rounded so as to give the branches a sort of bulbous termination. 



Among the Algte collected in Texas by Prof. Ravcncl, is a dried specimen CXo. 

 100), labelled "On Bark, Houston, Texas," which I cannot separate from this 

 species. It occurs in small tufts, which, as dried, arc of a very decided orange, 

 and, no doubt, were still brighter during life. The articles are not so irregular as 

 in Mr. Austin's specimens, but excepting in this and color when dried they agree 

 ^very well. Besides these I have several specimens from the same source, which 

 are in extended mats and agree in all respects with their northern brethren. 



Our American form appears to attain a greater diameter in its individual fila- 

 ■ ments than does the European variety, but I know of no other character separating 

 : it from tlie latter ; and consequently must consider them identical. The measure- 

 ment given is an extreme one, .009" being commonly the limit. 



! 



I Genus BULBOTRICHIA, Kutz. 



Fila iiulistiucto articulatiX, aclirua, firnia, I'aiiiosa ; vaini iu apice intumcsccntes, sporangia con- 

 stituentcs. 



' Filaments indistinctly articulate, translucent, firm, branched; the ends of tlie branches swollen so 

 as to form sporangia. 



B. albida, Wood (sp. nov.). 



B. strato albido, coriaceo vel crustaeeo ; fills arete intcrtextis, enorniiter ramossissimis, coloris 

 e.xpertibus; sporaugiis viridibus. 



Hab. — In muscis, Northern New Jersey ; (Austin.) 



Forming a white leathery or crustaceous stratum ; thread closely interwoven, irregularly and 

 plentifully branched, colorless ; sporangia greenish. 



Remarlcs. — This curious little plant, which was sent me by Prof Austin, occurs in 

 minute white patches growing on mosses at the base of stumps in woods. Some- 

 times these are encrusted abundantly with the carbonate of lime, when they are 

 hard and crustaceous. The sporangia appear to vary greatly in size ; sometimes 

 they resemble very closely a single spore (probably their commencing stage). The 

 bases of the branches are rarely, if ever, furnislicd with the bulbous swelling, given 

 by Rabenhorst as a generic distinction, but such enlargements do occasionally 

 occur in the course of the filaments and branches. The filaments are composed 

 of a scries of cells, wliich are in places long, and have their end walls thin and not 

 readily seen. 



Fig. 5, pi. 16, represents a part of a plant magnified 460 diameters. 



! Family Cn.ETOPHORACE.E. 



Algre aquatics vel palustres, rarius terrestres, plcruniqne nionoieas vel dioicae. Fila varia, sa>po 



dichotoine ramosa, baud raro fasciculatim ramnlosa, plcrumque in coespites vel pulvinulos cuniuhita, 



, in muco gelatinoso sublicjuido vel firnio nidulantia. Propagatio fit tnni oos])oris, tuni zoogonidiis. 



I Zoogonidia oriuntur aut singula aut geminis aut cytioplasmatis divisione 8-lC in quoquc sporangio. 



