Lemaneaceae of the United States. 219 
near the base, perfect and irregular in middle region, and 
broad and regular at the distal end. At maturity antherid- 
band sometimes constricted because the tissue here ceases to 
grow, sometimes prominent by hypertrophy, when a prominent 
ring is formed. Procarps in the middle of the procarp-zone. 
Spores 35 m -45 F- 
Note. This species is subject to great variations dependent 
upon the nature of the stream. Where the water is shallow and 
not very swift, the sexual shoots are strongly arcuate, short, and 
very stout. In deep water with a strong current they are 
nearly straight, and stout. In deep water where the current 
eddies below rocks, or is slow, they are stout at base, and the 
remainder capillary during the period of fertilization ; but if 
they mature before the capillary portions are broken away, 
they are generally stout throughout. Some of the largest 
specimens of this species I collected in the Broad river at 
Columbia, S. C. In Morgan’s Creek, Chapel Hill, N. C., 
specimens of the arcuate form were found on a level rock at 
the head of the upper rapids, Otey’s retreat. At lower rapids 
there is a place where the water is never lower than 25 cm. -40 
cm. and is always comparatively slow. Here grow specimens of 
the sterile Chantransia- form, which develop from year to year 
without producing sexual shoots. Near this, in the turbulent 
water, the Chantransia - form is fertile. At Columbia, S. C., 
the fertile Chantransia - form is somewhat smaller. 
5. Lemanea grandis Atk. 
E n to thrix grande Wolle, Bull. Torr. Bot. Club, 1887; 
Wolle, Rab. Alg. Europ. 2538. 
Tuomeya grande Wolle, Fresh Wat. Alg. U. S., pi. 66, 
Figs. 2-8, 1887. 
Chan transia-ioxm unknown, as the material was collected in 
midsummer. Sexual shoots olive-brown or blackish, rather 
slender, arcuate, very slightly undulate in the more fully 
developed specimens ; cortex of two to three layers of cells 
at maturity ; central axis with surrounding filaments very 
compact and tough ; walls of the sexual shoot very rigid at 
