188 FRESH-WATER ALG^ OF THE UNITED STATES. 



BemarJcs.-Vrol Harvey says (Smithsonian Contributions) :» I Wr^^ 

 North American specimens from Milton, Saratoga County, N. Y., and from Lake 

 Erie; also from the Mexican Boundary Surveymg Expedition. 



CI. fracta, Dillw. ,. 



Clad prima juventute affixa sed postea libera natans et caaspites formans ; ram^ ramuhsque 



is divri atis,nonnunquam refractis; ramulorum cytioplasmate non spirahter ordinate ; 



^ZLZl s.pe crassissimo ; cellulis fertilibns baud terminalibus, plerumque m raruulorum 



medio, aut eorum basi. 

 Syn.-Gl. fracta, (DiLW.) Rabenhorst, Flora Europ. Algarum, Sect. III. p. 334. 

 ffab.-In flumine Schuylkill, prope Philadelphia; Wood. West Point, New York; Provi- 



dence, Rhode Island ; Bailey. 

 In the young state fixed, but afterwards floating free and forming matted masses ; branches and 



branchlets scattered, divaricate, somewhat refracted; cytioplasra of the branches "o spirally 



arranged ; cytioderm often very thick; fertile cells not terminal, mostly m the middle of the 



branches, sometimes in their base. 



CI. brachystelecha, Rabenhorst. 



- C. per totam vitam innata, obscure viridis, sicca pallida, pygrasea, 2-4, rarius 6 linea longa, 

 ramosissima, intricata, plerumque culmigena ; ramis primariis ,V"— ?V"= 0.00295"— 0.0022 

 crassis, ramulis ultftnis ^V"-tV" = 0.00147"- 0.00128" crassis; articulis diametro 4-12 

 plo longioribns ; cytiodermate subcrasso, hyalino, subtiliter plicato-striato ; cytioplasmate 

 imprimis cellularum superiarum laxe spiraliter ordinato. (R.) 



Syn.—Gl. brachystelecha, Rabenhorst, Flora Europ. Algarum, Sect. III. p. 343. 



Bab.— Pio-pe Philadelphia ; Wood. 



Fixed through the whole life, obscure green, pale when dried, dwarfish, 2-4, rarely 6 lines long, 

 very much branched, intricate, mostly attached to culms; primary branches 0.00295" — 

 0.0022" thick, ultimate ramull COOUt" — 0.00128" thick ; articles 4-12 times longer than 

 thick; cytioderm thickish, hyaline, subtilely plicately striate; cytioplasm, especially of the 

 upper cells, laxly spirally arranged. 



Remarhs. I have notes of having identified this species at some time, but, 



having kept neither specimens nor detailed memoranda, have simply copied the 

 description of Prof. Rabenhorst. 



Family OEDOGONIACE^. 



AlgEe monoicae vel dioics. Fila articulata aut simplicia aut ramosa, cellula basali obovato-clavata, 

 basi plerumque lobato-partitia vel scutata innata. Propagatio fit turn zoogonidiis turn oosporis 

 fecuudatione sexuali ortis. Zoogonidia formantur singula in quavis cellula, forma late ovali vel 

 globosa, polo antico achroo corona ciliorum vibratoriorum praedita. 



Oogonia singula vel plura (2-5) continua, plus minusve tumida, in quoque oospora singula, 

 matura rubro- aut flavo-fusco-colorata, ante germinationem in zoosporas plerumque quatuor dilabens 

 se format. 



Antheridia brevi-filiformia, 1-2-3-1 0-articulata, plerumque singula aut oogonio aut filo vegeto in- 

 sidentia aut in individuis variis ssepe cellula obovato-clavata subtentata. 



MonsBcious or disecious algse. Filaments articulate, either simple or branched, fixed by the basal 

 cell which is obovate-clavate, mostly with its base lobately parted or shield shaped. 



Propagation sometimes by zoospores, sometimes by resting spores, the result of sexual impregna- 

 tion. Zoospores formed simply in certain cells, broadly oval or globose, their anterior end trans- 

 parent, and furnished with a crown of vibratile cilia. Resting spores single or in series of from 



