THE MARINE ALG.E OV NEW ENGLAND. 157 



incbes loiv^, braiK'lu'S oloiii;atod, iiTe;;iilarly i)laced, clotlieil bcluw with 

 iuimeix)us, short, siibiihito bniiichlets, thickeiieil and nearly naktnl near 

 the apex, wliich is often inueli in(iir\ed ; tetraspores zonate, borne in 

 somewhat swoUen branehh'ts ; eystoearps snb^lobose, mnnerons, on di- 

 varieately branehed spineseent branehk^ts. 



New Uedford, Mass., IFarvei/ ; Woo<rs I loll, W. G. F. ; Orient, L. I., 

 ^fiss Booth : and southward to the* West Indies. 



In four or live fathoms of water. 



A common species of the West Imlies, and probably not rare in Lonj; Island Sonml, 

 althonj^h not very common. It is nsnally finnnl washed ashore in sheltered places 

 like the Little Harbor. Wood's H(dl, altera heavy blow, where one sometimes finds 

 intricately twisted tufts two teet in diameter. With us eystoearps have not been seen, 

 but the frond is very well <levi'loped on our coast. It may be reco<^nizetl by the yel- 

 lowish-purple color, by the loni; branches covered with short, subulate branchlets, ami 

 especially by the swollen, naked a])ices, which are rolh'd strongly inwards or almost 

 circiiuite. Fertile specimens from the West Indies are more robust and do not s<» frc- 

 • luently have inrolled apices. The species does not adhere well to paper in drying;. 



Suborder GELIDIEiE. 



Fronds of a (U'nse cartilaginous structure, filiform or compressed, 

 branching ; antheridia in superficial patches ; tetraspores cruciate, boruo 

 in the cortical layer; eystoearps 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 eystoearps are bom in swollen terminal branches, 

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

 and there are two caqiostomes 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, and there is but one carpostome. 



GELIDIUM, Lam.x. 



(From ffclu, 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 ; eys- 

 toearps immersed in swollen branchlets, containing oblong or pyriform 

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

 walls of the cystocarp ; caq^ostomes usually one on each side of tho 

 frond. 



A genus of narrowly linear or nearly terete alj5;n of a dense structure, found in nearly 

 •11 parts of the world. The limits of tlic species are not well marked, because tho 

 ramificaticuis on which the principal specific distinctions depend are verj' variable. 

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



