38 FRESH-WATER AJ^QM OF THE UxNITED STATES. 



Filaments n.oiiilifor.n, witliowt sl.eatlis; spores spherical, yellow or yellowish-fuscous, mostly sin- 

 gle, variously placed as to the licturocysts and ordinary cells. 



Remarks.—Thc characters which I have given arc somewhat different and less 

 exacting than tliosc of Prof, llabenhorst, otherwise our American species would 

 hardly be covered by the diagnosis. Professor Harvey in his Phycologia Britan- 

 nica states that A. Jussicu liad preoccupied the name, Analana, by applying it to 

 a <Tenus of Euphorbiacew. The date of Bory's name is, however, 1823, whilst that 

 of Jussieu is 1824. Hence, it is the latter which must be changed. 



A. gelatinoxia, Wood. 



A. thallo mucoso gelatinoso, indefinite expanse, dilutissime brunneo, nonnihil pellucido ; tricho- 



matibus hand vao-jnatis, Icvitcr flexuoso-curvatis, nonnihil distaiitibus, baud intricatis, aut. 



dilute aureis aut dilute cseruleo-viridibus ; articulis globosis, homogcneis ; cellulis perdu- 



rantibus articuloruni diametro fere sequalibus, globosis, vel rare oblongis; sporis terminalibus, 



singulis, globosis (fusco-brunneis?). 



Syn. — A. gelatinosa, Wood, Prodroraus, Proc. Amcr. Philos. Soc, 1869, 126. 



JJab. — Prope Philadelphia. 



Thallus gelatinous, mucous, indefinitely expanded, somewhat pellucid, with a brownish tinge; 

 filaments not vaginate, somewhat curved, rather distant, not intricate, either a light golden- 

 yellovF or light bluish-green; joints globose, homogeneous; heterocysts about equal to the 

 filaments in diameter, globose or rarely oblong ; spores terminal, globose. 



Remarks. — The color of the shapeless mass of jelly of which the frond is com- 

 posed is a light.brown with, in places, a decided reddish or flesh-colored tint. The 

 heterocysts are either interstitial or terminal, no hairs were detected on them ; 

 they are mostly globose and only occasionally are they oblong. 



Fig. 4, pi. 2, represents a filament of this species magnified 750 diameters; the 

 color of the endochrome of the large spore was possibly due to its being dead. 



A. flos aquae, (Lyngb.) Ktz. 



A libere natans, submembranacea, aeruginea; trichomatibus plus minus eurvatis, sa3pius circi- 

 natis; articulis sphrericis vel e mutua pressione modo ellipticis modo oblongo-quadratis ; cel- 

 lulis pcrdurantibus ellipticis singulis vel geminis; cytioplasmate pallide a;rugineo granulate 

 turbato ; sporis exacte globosis aureo-fulvis lucidis, singulis interjectis, articulorum diametro 

 subduplo majoribus. R. Species mihi ignota. 



D-Jam.— Artie. 0.00017"— 0,00025" ; diam. long cell. perd. 0.00018"— 0.00053"; spor. 

 0.00032"— 0.0004". 



Syn.—A.flos aquae, (Lyngb.) Ktz. Rabenhorst, Flora Europ. Algarum, Sect. II. p. 182. 



i7a6.— "Round Pond, West Point, New York." Prof. Bailey. Silliman's Journal, N. S., vol. 

 iii. 18 



Swimming free, submcmbranaceous, ajruginous; filaments more or less curved, very often eir- 

 eiiinate; articles spherical, or, from mutual pressure, elliptical or oblong quadrate; heterocysts 

 elliptical, single or geminate ; cytioplasm pale reruginous, granulate ; spores exactly globular, 

 golden-fulvous, bright, singly interspersed, nearly twice the diameter of the joints. 



A. ^ig^antea, Wood. 



A. thallo nullo, trichomatibus singulis et numeroso-consociatis, natantibus, rectis, in retate 

 juveni spiraliter eonvolutis ; articulis plerumque subglobosis, arete connexis, granulosis ; eel- 



