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136 THE MARINE ALGÆ OF NEW ENGLAND. SECT. II. Fronds without spines, cortical cells confined to a definitely limited band round the nodes, the internodes diaphanous. C. DIAPHANUM, Roth; Phyc. Brit., Pl. 193. Fronds brownish red, filaments two to four inches high, loosely tufted, main branches setaceous, rather stout, distantly forking, beset with short, lateral, dichotomous branchlets, apices incurved; tetraspores immersed, in whorls at the nodes; favellæ lateral, involucrate. Nahant, New Bedford, Mass.; Providence, R. I.; New York Bay, Harvey; Europe; California. The localities given are quoted from the Nereis. As far as our own experience goes, the present species is of very infrequent occurrence on the New England coast, although we have specimens collected at Lynn, Mass., and others from the vicinity of New York, collected by Mr. A. R. Young, which may possibly be referred to C. diaphanum. In almost all cases the C. diaphanum of American collectors is the C. strictum of the Phycologia Britannica a species closely related to the present, and agreeing with it in the fructification, but differing in ramification. C. diaphanum has rather stout leading branches, which are beset with secondary dichotomous branches which are alternately given off from the main branches, and which are much finer than the main branches, the tips being capillary. The general outline of the frond is pyramidal, and that of the principal branches and their ramifications is ovalelongated. In C. strictum there are no leading branches, but the filaments are of a pretty nearly uniform diameter, regularly dichotomous throughout, and form globose tufts. Both species differ from our other species, except C. Hooperi, in being of a brownish-purple rather than of a distinctly rosecolored tint, and both adhere closely to paper in drying. C. STRICTUM, (Kütz.) Harv. (C. strictum, Phyc. Brit., Pl. 334.—Gongroceras strictum, Kütz.) Fronds brownish red, filaments capillary, two to six inches high, densely tufted, branches uniformly dichotomous throughout, divisions erect, fastigiate above, apices forcipate; tetraspores immersed, whorled at the nodes. On Zostera and other marine plants. Common from New York to Cape Cod. This species forms large tufts at the base of Zostera in warm, shallow bays, and is often in company with Polysiphonia Olneyi. In the Little Harbor at Wood’s Holl it is found in large quantities, after a heavy blow, lying unattached on the mud, just below low-water mark. C. HOOPERI, Harv. (C. Hooperi, Harv., Ner. Am. Bor., Part II, p. 214.—C. Deslongchampsii, Farlow, in Report U. S. Fish Comm., 1875.) Fronds dark purple, one to four inches high, filaments procumbent and densely interwoven at base, above dichotomous, with short, erect, irregularly placed lateral branches, apices straight, erect, cortical cells forming a sharply defined band at the nodes, axile cells short above, becoming twice as long as broad below; rhizoidal filaments unilateral,
REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 137 single at the nodes, numerous, usually unicellular, often ending in irregular disks; tetraspores in a circle at the nodes, immersed in the cortical cells; favellæ? Forming tufts on mud-covered rocks at low tide. New Haven, Prof. Eaton; near New York, Mr. Young; Newport‚ R. I.; common from Nahant to Eastport. This species is not, as Harvey and Agardh supposed, very distinct, but, on the contrary, can scarcely be distinguished from C. Deslongchampsii, except in the tetraspores, which are immersed, not projecting as in that species. Both species inhabit similar localities, both are deep purple in color, are procumbent at the base, and have numerous rhizoids; the branching and erect tips are the same in both. Furthermore, as it occurs with us, C. Hooperi not unfrequently bears precisely such irregular botryoidal masses as are found on C. Deslongchampsii in Europe, and which are figured in the Phycologia Britannica. Harvey, as well as Nægeli and Cramer, doubts whether these masses are really favellæ, and, judging from American specimens, they are more probably monstrosities. In one case we found the distortions on a specimen bearing tetraspores, and Nægeli and Cramer have observed a similar case, a presumption against the favelloid nature of the swellings. Fully-matured tetraspores are to be desired, and it may be that they will be found to be prominent, as in C. Deslongchampsii, in which case the validity of the species would be more than doubtful. C. FASTIGIATUM, Harv., Phyc. Brit., Pl. 255. Fronds lake-red, densely tufted, two to five inches high, filaments capillary, dichotomous throughout, divisions erect, level-topped, apices erect or slightly incurved; tetraspores secund on the outer side of the branches, prominent; favellæ small, lateral, with a short involucre. On Zostera. Massachusetts Bay; Greenport; Newport; Long Branch, Harvey. This species is at present a puzzle. In American herbaria one frequently finds specimens labelled C. fastigiatum, and some specimens bear Harvey’s own handwriting. Unfortunately, the species is persistently sterile, for we have only twice found tetraspores in what seemed to be this species, and sterile specimens are hardly sufficient for determination in the genus Ceramium. What was apparently considered by Harvey to be his C. fastigiatum is common south of Gape Cod and forms beautiful tufts on Zostera. The color is a lake-red, the filaments are all capillary and regularly dichotomous, the upper segments being level-topped, so that when spread on paper the species has a regular outline. The apices are erect, not rolled inwards at the tip, and short rhizoidal processes are given off from some of the nodes. Harvey states that the tetraspores are prominent and secund on the outer edge of the branches, while Agardh says they are whorled at the nodes. In one specimen we found them as described by Harvey. It must be admitted that when sterile the species approaches too near C. tenuissimum, and it is much to be desired that a large set of fruiting specimens be examined to settle the disputed question of the tetraspores. C. fastigiatum is a species apparently not well known to continental botanists, who seem to have at times included it in other species without reference to British specimens. With us it is common, although, considering that there may be a doubt about the determination, we have only quoted the localities given by Harvey. By Agardh C. fastigiatum is considered closely related to C. Deslongchampsii, but judging by Harvey an specimens, both from Ireland and New England, we can hardly think that the two species are immediately related.
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