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160 THE MARINE ALGÆ OF NEW ENGLAND. SUBORDER SPONGIOCARPEÆ. Fronds solid, cylindrical, branching; antheridia in spots on upper part of fronds; tetraspores cruciate, immersed in the cortical filaments; cystocarps in external wartlike protuberances, composed of parallel filaments, spores obovate, densely packed around the surface of a cellular mass which surrounds the tip of a short pedicel. The present suborder was made by J. G. Agardh and Harvey to include a single species, Polyides rotundus, a species in several respects anomalous. The development of the cystocarps of that species was first made out by Thuret and Bornet, and a detailed account Was published in the Études Phycologiques. In its development the cystocarp of Polyides resembles that of the genus Dudresnaya. There is produced from the cells at the base of the trichogyne a number of filaments which wind amongst the short filaments, of which the wart-like bodies near the tips of the fronds are formed; These filaments come in contact with certain cells of the protuberances, which then divide and produce the spores. Although this indirect fertilization of the carpogenic cells by means of winding filaments is the same as is found in Dudresnaya, the mature cystocarp is different in the two genera. In Polyides the ripe spores are arranged in a regular layer around a small placenta, which is borne on a short pedicel produced from the carpogenic cell. In Dudresnaya coccinea the spores are irregularly grouped, around a placenta surrounding the carpogenic cell itself. In L. purpurifera, however, according to D. Bornet, the cystocarps more nearly resemble those of Polyides, and he thinks it not impossible to unite the two genera in one suborder. POLYIDES, Ag. (From πολυς [polus], many, and ιδεα [idea], form.) Fronds cylindrical, dichotomous, composed of interlaced branching filaments, consisting of elongated cells and curving outwards at the surface so as to form a cortical layer of horizontal filaments; antheridia in patches on the upper part of frond, consisting of short, densely packed filaments bearing clusters of antherozoids; tetraspores cruciate, immersed in the cortical layer; cystocarps in wart-like protuberances on the upper part of the frond. P. ROTUNDUS, Grev.; Phyc. Brit, Pl. 95. Fronds blackish red, cylindrical, cartilaginous, three to six inches long, attached by a disk, with an undivided stipe, which becomes above repeatedly dichotomous, apices obtuse; warts flesh-colored, numerous on the upper divisions of the frond. On stones in deep pools and in deep water. Common from New York northward; Europe. A species easily recognized by its regularly dichotomous, cylindrical frond, by its dark, almost black, color, and dense cartilaginous substance. When sterile it might be mistaken for Furcellaria fastigiata, a common species of Northern Europe, which may be expected to occur on our coast. In fruit, however, they are easily distinguished, since the cystocarps of Polyides are borne in external warts, while those of Furcellaria
REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 161 are in the somewhat swollen tips of the frond. The present species is usually found washed ashore from deep water, but on the northern coast is found also in deep tidepools. When dried it becomes brittle and does not adhere to paper. SUBORDER SPHÆROCOCCOIDEÆ. Fronds cylindrical or membranaceous, substance often very delicate; antheridia forming superficial patches or occasionally contained in sunken cavities; tetraspores cruciate, zonate, or tripartite, often collected in spots (sori) on the surface; cystocarps external, hemispherical or flask-shaped, spores arranged in moniliform filaments, which radiate from a basal placenta, carpostome distinct. The present suborder is by Agardh and some other writers divided into two, the Sphærococcoideæ, which include rather coarse cartilaginous algæ, which are cylindrical or somewhat compressed, but hardly membranaceous, and the Delesserieæ, which are rosy-red and of delicate <strong>text</strong>ure and distinctly membranaceous. The fruit, however, is very similar in both groups. The spores are arranged in subdichotomous filaments, which radiate from a basal placenta, which in some genera, as Gracilaria, projects far into the cavity of the cystocarp. The suborder differs from the Rhodymenieæ in that the moniliform arrangement of the sporiferous filaments is preserved even at maturity, and the filaments are distinct from one another and not held together by a gelatinous envelope. It must, however, be admitted that there are genera which seem to indicate a close relation between the two suborders. GRINNELLIA, Harv. (Named in honor of Mr. Henry Grinnell, of New York.) Fronds rosy-red, occasionally purple, delicately membranaceous, with a slender percurrent midrib, composed of a single layer, at the midrib of several layers, of large polygonal cells; antheridia in tufts on both sides of the frond; tetraspores tripartite, in swollen spots on the frond; cystocarps sessile on the frond, flaskshaped, spores in dichotomously branching filaments arising from a basal placenta. A genus comprising a single species, which is found from Cape Cod to Norfolk, separated from Delesseria because the tetraspores are formed in incrassated spots on the frond. The genus is too near Delesseria, of which it should perhaps form a subgenus. G. AMERICANA, Harv., Ner. Am. Bor., Part II, Pl. 21 b. (Delesseria Americana, Ag.— Aglaiophyllum Americanum, Mont.— Cryptopleura Americana, Kütz.) Pl. XIII, Figs. 2-4. Exs.—Alg. Am. Bor., Farlow, Anderson & Eaton, No. 64. Fronds diœcious, four inches to a foot and a half long, one to four inches wide, lanceolate, tapering at the extremities, occasionally bifid or proliferous, margin smooth or wavy; antheridia in small spots on both sides of the frond; tetraspores scattered over the frond in thickened spots; cystocarps scattered, sessile, flaskshaped. S. Miss. 59——11
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