Frond rises from stalk and widens into a flat, thick, leathery, oval expansion, one to two feet long, and one to three inches broad; [pg083] simple or lobed; surface sometimes roughened by collections of spores in dots; dark red, often glittering in the water with blue and purple tints. It is found on the Pacific coast. (Plate XX.) SUBORDER ~RHODOPHYLLIDEÆ~ GENUS ^Cystoclonium^ ^C. purpurascens.^ The translucent, fleshy, juicy main stem, one eighth of an inch or less in diameter, runs through the whole plant; irregularly branched all around main stem; branches again branch in same manner; branches attenuated at the base, and taper to a long point; smaller branches distended in places by spores into bladder-like swellings, hence the name; color rose-red to dark purple; plants exposed on the beach often faded to orange and white; six to eighteen inches long. It grows on rocks between tide-marks as well as in deep water. With the exception of /Ceramium rubrum/, this is the most common red alga on the eastern coast from New York northward. It differs from /Rhabdonia/ in having bladdery branches; otherwise it is easily mistaken for it. ^C. cirrhosa.^ Ends of branches terminate in spirals like tendrils; otherwise identical with /C. purpurascens/. (Plate XX.) GENUS ^Euthora^ ^E. cristata.^ Frond one inch to five inches high, membranaceous, broadly spreading; divisions wide and numerous, ultimately becoming fine like minute branchlets, each one of which, under a glass, shows a notch in the tip. This beautiful, bright-red alga is found in abundance north of Cape Cod. It differs from /Delesseria alata/ in having no midrib or veins. It grows in deep water on stones, shells, and algæ. (Plate XXI.) GENUS ^Rhodophyllis^ ("/Rosy leaf/") ^R. veprecula.^ Frond two to five inches long, one fourth of an inch to one and one half inches broad, membranaceous, forked; margin covered with leaflets which are in turn edged with minute branchlets; color deep red. It is found on the northern New England coast. (Plate XXI.) GENUS ^Rhabdonia^ ("/A wand/") ^R. tenera.^ Frond six to eighteen inches long, cylindrical, fleshy, translucent, juicy; irregularly and profusely branched, branches longest at the base, erect, tapering at both ends, numerous branchlets; sometimes the main stem runs through the plant, sometimes it is lost in the [pg084] branching; spore-masses sometimes form knotty bunches on the side of branches. It resembles a large /Cystoclonium purpurascens/. It is characteristic of Long Island Sound, and is not found north of Cape Cod, but common from there southward along the whole Atlantic coast. (Plate XXI.) ^R. Coulteri.^ This species is common on the Pacific coast, and differs from /R. tenera/ in having a more pronounced leading stem, and branches shorter and crowded at the top of the frond. GENUS ^Eucheuma^