THE MARINE ALG.E OF NEW ENGLAND. 171 



risiiijr from a creeping base, aipillary, alternately (leeomi)oun(l, branches 

 nuiltitid, attenuate, branchU'ts filitorm, internodes ouco and a lialf a> 

 long as broad. 



Var. Wkstpointensis, llarv. 



More slender and delicate. 



Jackson Feny, N. Y. ; Newburyport, Mass., i/rtrrey; Providence, K. 

 T., Mr. Ohmj; Gloucester, Mass. ? ir. (/. F. The variety at West Point. 



The present species is with tlilliculty <lislingnish«'(l from P. Olneyi, which, in its turn, 

 too closely approaches /*. Ilarrcyi. The two last-nanieil species are attached hy a 

 small disk, and the filaments do not rise from a creeping base, as iu the present spe- 

 cies. The vertical filaments of /*. snbtllissima are of a purple color, and are fine and 

 soft, and the cells are not much longer than broad. We have seen specimens collected 

 l»y Mi\ Olney near Providence which may with certainty be referred to the present, and 

 have found fioatingin ditches at Gloucester tufts of a very dark, delicate species which 

 may pn>bably be referred to it. The specimens were apparently washed from some 

 muddy shore, but the creeping basal lilaments could not bo seen. Gloucester col- 

 lectors should search for the plant iu muddy ditches towards Little Good Harbor. 



P. Olneyi, Ilarv., Xer. Am. Bor., Part If, PI. 17 h.— Dough Balls. 



Fronds brownish red, densely tnfted, from two to five inches high. 

 fdaments capillary, much branched, branches patent or divaricate, 

 decomponnd, attenuated above, with scattered slender branchlets,. 

 internodes three or four times as broad below, becoming shorter above; 

 antheridia ellipsoidal, not mucronate ; cystocaq^s broadly ovate, nearly 

 -essile. 



On Zoster a. 



From Xew York to Ualifax, most common south of Cape Cod. 



The present species passes l>y numerous forms into P. Uarveyi, and in spite of tho 

 marked ditlerence in the typical forms of the two species, the question remains to bo 

 settled whether P. Olneyi is not a slender variety of P. Uarveyi. In Its typical form 

 P. Olneyi forms dense soft tufts, sometimes called dough-balls by the sea-shore popula- 

 tion. The filaments are divaricately branched below, but tho upper branches are 

 slender and erect and beset with fine byssoid branchlets. When old, however, the 

 " wer branches become rigid, and the branchlets rather spine-like, as in the next spe- 



' s. Both P. Olneyi and P. JIarveyi are very common from Cape Cod to New York, 

 growing usually on Zostera in shallow, quiet bays. As they mature they fall from tho 

 Zostera and are blown into small coves, the bottoms of which are sometimes almost 

 cari>eted with the globose tufts of these two species, which lie loosfdy on the bottom. 

 Tin- tvi>i< al fonus of the ]»resent simhIcs collai>se at once when remove<l from the 



P. IlAiiVKVi, P»ail.; Xi*r. Am. lior.. Part 11. PL 17 a.—Xujgcr ILnr. 

 PI. XV, Fi^. 3, 4. 



Fronds blackish red, globosely tufted, lilaments two to six inches 

 high, setaceous, when young with a leading axis, becoming divaricately 

 much branched, branches .alternately decomimund, patent, often angu- 

 larly brnt, beset with numerous short, sim])lr or forked, si)ineliko 



