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THE MARINE ALGÆ OF NEW ENGLAND.
branchlets, internodes all short, never more than twice as long as broad; antheridia
ellipsoidal, not mucronate; cystocarps broadly ovate, on short pedicels.
On Zostera and other plants.
Common in Long Island Sound and found in several place in Massachusetts Bay;
Goose Cove, Squam, Mass.
The typical form of the species is closely related to P. spinulosa, Grev., found in Scotland and in the
Mediterranean and Adriatic Seas, where, however, it does not appear to be at all common. We once
collected specimens at Antibes, France, and certainly at first sight it could not be distinguished from P.
Harveyi. In the typical P. Harveyi the branches are rather rigid and the branchlets are spine-like and
sometimes revolute. As the plant grows old the finer branchlets disappear, and there is left an irregular
mass of coarse filaments beset with revolute branchlets, forming the P. arietina of Bailey, which is in
the Nereis considered a variety of P. Harveyi. It is, however, rather an autumnal condition than a
proper variety. The upper portion of the fronds of P. Harveyi are sometimes slender and byssoid, and as
it is a well-known fact that the branchlets of Polysiphoniæ have the power of falling from their
attachments and producing new plants, it may be, as has already been suggested, that P. Olneyi is the
byssoid condition of P. Harveyi.
Polysiphonia Americana, Reinsch, Contrib. ad Algolog. et Fungolog., p. 50, Pl. 33 a, as far as can be
judged by the plate, closely resembles some forms of P. Harveyi, except in the color, which as given by
Reinsch is bright pink. It is said by Reinsch to resemble P. arietina, Bailey, in general appearance, but
to differ in the erect, subdichotomous filaments, whose joints are bicellular.
SEC. II. Siphons four, main branches corticated, ultimate branches without
cortication.
P. ELONGATA, Grev.; Phyc. Brit., Pls. 292, 293.—Lobster Claws.
Fronds dark red, six to twelve inches long, robust, cartilaginous, irregularly
branched, lower branches naked, upper beset with closely set, alternately multifid
branchlets, which taper at the base and apex, cortications covering all but the
younger portions of frond, section of branches showing four large siphons, with
secondary siphons and a rather thick cortex; cystocarps ovate.
Gloucester, Lynn Beach, Squam, Wood’s Holl, Gay Head, Mass.
One of the largest but less common Polysiphoniæ, which is more abundant in the spring than at any
other season. The species is perennial and in late summer and autumn the branchlets fall off, leaving
the lower and coarser branches, which persist through the winter, and in the following spring produce
at the apices tufts of delicate, deep-red branchlets. It is recognized by its long cartilaginous main
branches, which are nearly naked, and which bear tufts of filaments at the apex. The popular name of
lobster claws is tolerably appropriate.
P. FIBRILLOSA, Grev.; Phyc. Brit, Pl. 302.
Fronds brownish yellow, four to ten inches high, broadly pyramidal, rather robust
below, becoming slender above, with an undivided axis or divided near the base into
several long, main branches, secondary branches alternate, several times pinnate,
fibrillose, with short, scattered‚