24 
spherical tubercles, containing a tuft of filaments, bearing the spores, also tetraspores 
in definite spots. 
No. 85. D. Americana . Harv. A dull red, becoming brighter in fresh water, 
2 to 15 inches long, from July to November, at Hurlgate, the Narrows, and other 
places ; common but not abundant. 
No. 86. D. sinuosa. Good and Woodw. Stem elongated, branched, with ob- 
ovate, deeply sinuate toothed leaves, nerves opposite. 
Very abundant a few miles east of us, and in Massachusetts Bay, occasionally floats into our harbor. 
Genus, PLOCAMIUM. Lamour. 
Pinky red, linear, compressed or flat, ribless or faintly nerved, distichous and 
much branched ; fructification, spherical tubercles, sessile or stalked, also simple or 
branched pods, stichidia, containing a double or single row of tetraspores. 
No. 88. P. coccineum. Huds. Narrow cartilaginous, compressed, branches 
spreading, alternate, irregular, ramuli often secund, pectinate on inner edges. 
Floating in small quantities, rare ; it is probably brought by tidal currents from Rhode Island and Mas¬ 
sachusetts coast, where it is rather abundant. 
Family XI. RHODYMENXACBiB. Har. 
Purplish or blood red ; expanded or filiform, inarticulate, superficial cells min¬ 
ute, irregularly packed; fructification, globose or hemispherical conceptacles exter¬ 
nal or half immersed, spores in the pericarp on a central placenta ; tetraspores in 
patches immersed through the whole plant. 
Genus, RHODYMENIA. Grev. 
Membranaceous or sub-coriaceous, ribless, veinless, cellular, fruit, convex tu¬ 
bercles. 
No. 90. R. palmata. L. Sub-membranaceous, purplish red, broadly wedge 
shape, irregularly cleft, margin winged with proliferous leaflets ; tetraspores distri¬ 
buted over the whole surface in cloud-like spots. 
Rarely found in our Bay; grows rather abundant in the Sound near us; 6 to 15 inches long. I have 
only one plant. 
Genus, GRACILARIA. Grev. 
Filiform or rarely flat, carnoso-cartilagenous, the central cells large ; fructifica¬ 
tion, convex tubercles. 
No. 92. G. multiparlata. Clem. Cartilagineo-membranaceous, tender, brit¬ 
tle, dull purplish red, deeply cleft in an irregularly dichotomous manner; the apices 
acute, tubercles conical, prominent, scattered over the surface. 
Summer and autumn, common on all our shores; abundant at Staten Island, Red Hook, Kavon Point, 
Jersey City, and Hurlgate, at and below low water mark. Turns black in drying, and does not adhere to 
paper ; 2 to 10 inches long. 
