^C. diaphanum.^ This species has comparatively stout leading branches, with secondary alternate branches which are finer than the main stems and divide in a forking manner throughout, and ultimately become very fine. The color is brown or purplish-red, distinctly banded. It grows on eel-grass and algæ, and is found from Cape Cod to New York. (Plate XXXIV.)
^C. fastigiatum.^ Filaments of hair-like fineness and of about same size throughout; branched in regular forking manner throughout, the divisions being wide and distant at the base, but gradually becoming closer and narrower as they reach the top; the upper segments about equal, giving a level top and regular outline in mounted specimens; the terminal forks erect, or less incurved than in other species; small points or branchlets emanate from some of the nodes or joints between the bands of color; tufts globe-shaped, two to five inches high; color lake-red. This species grows on mud-flats and mud-covered rocks as well as on algæ and eel-grass.
^C. tenuissimum.^ Fronds two to four inches high, densely tufted; the forked divisions very wide or open; color rose-pink.
Variety ^patentissimum^. Fronds small; the forked divisions distant and very wide open. A mounted specimen appears somewhat like network. The species is common in Long Island Sound. (Plate XXXIV.)
^M. Coulteri.^ Cylindrical, slightly flattened main stem; branches set uniformly and alternately, short at the base, gradually lengthening as far as the center, and from there diminishing to the apex of the stem, giving a leaf-like outline. The same mode of branching and the same outline are repeated in the branches. The ultimate divisions are like forked divisions, and are somewhat incurved. The plant is six to eight inches high, and in color is of many shades of red and pink. It is found in abundance on the Pacific coast at all seasons. (Plate XXXV.)
^M. borealis.^ Branches and branchlets placed on one side of arched main stems; secondary branches curved in opposite direction and bearing branchlets, also divided on one side only; color dark brown. It is found on the northern Pacific coast. (Plate XXXV.) [pg094]
^G. capillaris.^ Frond six to ten inches high, solitary or in tufts; main stem cylindrical, solid above, hollow below; from about an inch above the base densely beset with short, wide-spreading branches arranged evenly and all around the stem; branches again branched in the same way; branches and branchlets attenuated at base and apex; soft, tender, juicy; shrinks much in drying. The species is easily recognized by its delicate gelatinous substance, tapering branchlets, and brilliant red color. It is found in early summer in tide-pools on the New England coast.