Myxophycese, Rivularlaceoe, Calothrix. 631 



f. 2. — Fronde csespitulosa; filaraentis simplicibus, aetate provocta 

 valde elongatis; vaginis truncatis et apertis, ad 12 {ji. diam., in 

 ffitate juvenili modice brevibus et in setam modice longam achroam 

 productis; trichomatibus breviter articulatis, subtiliter granuhitis, 

 continuis varieve interruptis, ad 7 \i. diam.; vaginis firmis, modice 

 crassis, siepe distincte hunellosis, colore expertibus; heterocystis 

 subglobosis. 



Ilab. in aestuario « Stonington, Conn. » Amer, bor. (Wood). 



57. Mastigonema elongatum Wood Freshw. Alg. of the U. S. pag. 53, 1439 

 t. V, f. 1, a, b, Prodr. p. 128, Wolle Freshw. Alg. of U. S. p. 243, 



t. CLXXIV, f. 9. — Strato initio subgloboso, postea sa3pe nonnihil 

 fusiformi (?) nigro-viridi, lubrico, firmo; filamentis aerugineis, valde 

 elongatis, flagelliformibus, ad 6 [x. diam. ; trichomatibus articulis 

 ;egre conspicuis sed saepius breviter articulatis, interduiu al geni- 

 cula valde constrictis, apice interdum truncatis sed plerumque in 

 pilum longum, achroum, flexuosum productis; vaginis achrois, 

 arctis, ssepe apice truncatis; heterocystis globosis vel subglobosis. 

 Hab. in « Carp River » (Wood); in lacu « Kilpatrick, Minn. » 

 Amer. bor. (Tildenj. 



58. Mastigonema sejunctum Wood Freshw. Alg. of the U. S. p. 53, i440 

 t. 4, f. 2 a, Prodr. p. 128. — Thallo csespitoso, molli, epiphytico; 

 filamentis simplicibiis; trichomatibus articulis plerumque incon- 

 spicuis sed interdum breve, interdum longe-articulatis, continuis, 

 rarius interruptis, apice attenuatis, flavo-olivaceis aut viridibus, 

 sparse granulatis; vaginis plerumque amplis et distinctis, hyalinis, 

 ssepius valde undulatis, apice plerumque valde amplis et in fibrillas 

 solutis; heterocystis diametro subtequalibus; sporis ignotis. 



Hab. in plantarum aquaticarum foliis « Carp River, Michig. » 

 (Wood) et in lacu « Harriot, Minn. U. S. » xAmer. bor. (Tildenj. 



59. Mastlgonema fibrosum (Wood) WoIIe Freshw. Alg. of U. S. p. 244, I44i 

 tab. CLXXIV, f. 8, Mastigothrix fibrosa Wood Freshw. Alg. of 



the U. S. p. 54, t. 5, f. 3, Prodrom. p. 129. — Fronde dilute vel 

 cteruleo-viridi v. olivaceo-viridi v. subcieruginea; filamentis inferne 

 haud articulatis, sursum soepe breviter articulatis, apice aetate pro- 

 vecta in setam hyalinam, distincte articulatam, longam productis; 

 vaginis achrois in filamento immaturo, apice distinctis, latis, hya- 

 linis, basi modice crassis, arctis, in filamentis maturis basi arctis, 

 indistinctis, apicem versus in fibrillas dissolutis, apice absentibus; 

 heterocystis globosis, interdum geminis, 



Hab. prope Philadelphiam Amer. bor. (Wood). 



