216 Atkinson. — A Monograph of the 
1849; Rabh., Flor. Europ., etc. in. 1864-68; Sird’t., Ann. 
d. Sci. Nat. 1872. 
Lemanea catenata Wood, Fresh Wat. Alg. U. S. 1872 ; 
Wolle, Fresh Wat. Alg. U. S. 1887. 
Lemanea fluviatilis Wolle, Fresh Wat. Alg. U. S. ex 
parte, 1887. 
Chantransia- form 2 mm. to 3 mm. long, of a dark violet 
color unless faded with age ; cells 30 fx. to 40 /x. in diameter, 
filaments of nearly the same diameter throughout ; branching 
below alternate, then unilateral, alternate or rarely opposite. 
Sexual shoot arising at the ends of a principal axis of the 
Chantransia-iorm, or on a short branch, confined near the 
base, of a violet color when young, sometimes fading out in 
age, young ones blacking when dry ; usually simple, some- 
times branched, the branches fasciculate, developing from 
procarps in the middle of the procarp-zone. Sexual segments 
regularly constricted ; antherid-band at the time of fertiliza- 
tion broad, usually regular, sometimes interrupted near the 
base ; at the time of fertilization antherid-band of a lighter 
color than the adjacent parts when in water. Antherid-zone 
sometimes increasing after fertilization by hypertrophy of the 
tissue at the base of the antheridia. Procarps developed in 
the middle of the procarp-zone. 
Habitat . Santa Cruz, Cal., Dr. C. L. Anderson ; Oakland, 
Cal.; Eastern Oregon, W. C. Cusick, No. 1353; Diamond 
Mts. Nevada, Sereno Watson, U. S. Geol. Expd., 40th 
Parallel, No. 1546 ; California (Herb. Wolle, L. fluviatilis). 
Note. At the time of fertilization this species is readily 
determined by the strong contrast, when in water, in color 
of the antherid-band with the procarp-zone. After fertiliza- 
tion this is not so distinct, but the tissue beneath the 
antheridia in the band can easily be seen under the micro- 
scope. Specimens dried when nearly or quite mature often 
lose nearly all or all of the violet color ; but as they mature 
there appears a dark region in the middle of the procarp-zone 
which has the appearance of a dark band, narrow when the 
spores are quite young, but broader when they are mature, 
