THE MARINE ALG.E OF NEW ENGLAND. 157 



inches long, branches elongated, irregularly placed, clothed below with 

 numerous, short, subulate branchlets, thickened and nearly naked near 

 the apex, which is often much incurved ; tetraspores zonate, borne in 

 somewhat swollen branchlets ; cystocarps subglobose, numerous, on di- 

 varicately branched spinescent branchlets. 



New Bedford, Mass., Harvey ; Wood's Holl, W. G. F. ; Orient, L. I., 

 Miss Booth ; and southward to the West Indies. 



In four or five fathoms of water. 



A common species of the West Indies, and probably not rare in Long Island Sound, 

 although not very common. It is usually found washed ashore in sheltered places 

 like the Little Harbor, Wood's Holl, after a heavy blow, where one sometimes finds 

 intricately twisted tufts two feet in diameter. With us cystocarps have not been seen, 

 but the frond is very well developed on our coast. It may be recognized by the yel- 

 lowish-purple color, by the long branches covered with short, subulate branchlets, and 

 especially by the swollen, naked apices, which are rolled strongly inwai-ds or almost 

 circinate. Fertile specimens from the West Indies are more robust and do not so fre- 

 quently have iurolled apices. The species does not adhere well to paper in drying. 



Suborder GELIDIEiE. 



Fronds of a dense cartilaginous structure, filiform or compressed, 

 branching ; antheridia in superficial patches ; tetraspores cruciate, borne 

 in the cortical layer; cystocarps formed in swollen branches and com- 

 posed of spores arranged singly or in short filaments on the surface of 

 an axile or parietal placenta, carpostomes present, often two in number; 



Rather a small order of dark-colored, rigid sea-weeds, whose fronds are formed of 

 densely packed cells, and whose cystocarps are born in swollen terminal branches, 

 but are not strictly external. In Gelidium the spores are sessile on an axile placenta, 

 and there are two carpostomes on the opposite surfaces of the fronds. In Pterocladia 

 the placenta is attanched to the lateral wall of the cystocarp, the spores are borne few 

 in a row, aud there is but one carpostome. 



GELIDIUM, Lam.x. 



(From geln, frost, and, secondarily, gelatine.) 



Fronds cartilaginous, terete or compressed, decompound-pinnate, 

 formed of long cylindrical cells in the axis, surrounded by roundish 

 cells which become small and polygonal at the surface; antheridia in 

 superficial patches ; tetraspores cruciate, scattered in the cortex ; cys- 

 tocarps immersed in swollen branchlets, containing oblong or pyriforin 

 spores borne on an axile placenta which is attached by filaments to the 

 walls of the cystocarp ; carpostoines usually one on each side of the 

 frond. 



A genus of narrowly linear or nearly terete algse of a dense structure, found in nearly 

 all parts of the world. The limits of the species are not well marked, because the 

 ramifications on which tho principal specific distinctions depend are very variable. 

 The genus is recognized on our coast by the peculiar cystocarps, which are formed in 



