188 FRESH -WATER ALG.E OF THE UNITED STATES. 



RemarJcs. Prof. Harvey says (Smithsonian Contributions): "I have received 

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

 Erie ; also from the Mexican Boundary Surveying Expedition." 



CI. fracta, DILLW. 



Clad, prima juventute affixa sed postea libere natans et csespites formans ; ramis ramulisque 

 sparsis, divaricatis, nonnunquam refractis ; ramulorum cytioplasmate non spiraliter ordinato ; 

 cytioderrnate saepe crassissinio ; cellulis fertilibus baud tcrminalibus, pleruinquc in ramulorum 

 medio, aut eorum basi. 



Syn. Cl. fracta, (DiLLW.) RABENUORST, Flora Europ Algarum, Sect. III. p. 334. 



Hab In flnmine 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 ; cytioplasm of the branches not spirally 

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

 branches, sometimes in their base. 



Cl. brachystelecha, RABENHORST. 



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



ramosissiraa, intricata, plerumque culmigena ; ramis priraariis ^V" ?V"= 0.00295" 0.0022" 



crassis, ramulis ultimis ^'" Jo" = 0.00147" 0.00128" crassis; articulis diaraetro 4-12 

 plo longioribus ; eytiodermate subcrasso, hyalino, subtiliter plicato-striato ; cytioplasmate 

 imprimis cellularnm snperiarum laxe spiraliter ordinato. (R.) 



Syn.Cl. brachystelecha, RABENHORST, Flora Europ. Algarum, Sect. III. p. 343. 

 Hab. Prope 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 ramuli 0.00147" 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. 



Remarks. 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^E. 



Alg33 monoicae vel dioicse. Fila articulata aut simplicia aut ramosa, cellula basali obovato-clavata, 

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

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

 globosa, polo antico achroo corona ciliorum vibratoriorum prsedita. 



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

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

 se format. 



Antheridia brevi-filiformia, 1 -2-3-1 0-articnlata, plernmque singnla aut oogonio aut filo vegeto in- 

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



Monoecious 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 



