THE MARINE ALG^ OF NEW ENGLAND. 173 



simple branchlets, ultimate divisions capillary, tufted ; antheridia ob- 

 long, terminal ; cystocarps ovate. 



On stones and Zostcra at low-water mark. 



Lynn, Mass., Harvey; Wood's Holl, Noank, Orient Point, Newport, 

 and several places in Long Island Sound ; Europe. 



Rather a common species in sheltered places south of Cape Cod, but only known 

 northward from the reference of Harvey. It is smaller and more slender than the last 

 species and the branches are not naked, but fibrillose. The present species is more 

 nearly related to P. violacea, of which Harvey suggests that it may be a variety. 

 The last-named species is more decidedly red in color, is a larger plant, and although 

 the ultimate branches are in tufts, as in P. fibrillosa, the larger branches are destitute 

 of the librillose branchlets characteristic of the latter species. 



P. violacea, Grev. ; Phyc. Brit, PL 209. 



Fronds brownish red, sis inches to two feet long - , elongated, pyramidal, 

 usually with an undivided main axis, which has several long, widely 

 spreading branches near the base, main divisions robust, becoming 

 capillary at the tops, branches rather naked below, bearing above numer- 

 ous multifld branchlets, ultimate branchlets densely tufted; antheridia? 

 cystocarps broadly ovate, sessile or shortly pedicelled. 



Var. flexicatjlis, Harv. 



Branches very long, slender, angularly bent, much divided, divisions 

 patent and sometimes secund. 



In deep tide-pools on exposed shores and on Zostcra in deep water. 



Common from New York northward. Yar. fiexicaulis, Cape Ann; 



Portland, C. B. Fuller ; and northward. 



Ono of ( he commonest species of the genus, frequenting cold, exposed tide-pools, where 

 it has a dense habit and rarely exceeds a foot in length. When growing in deep water 

 it is long and slender. In spring it has a pink color, but late in the season it becomes 

 dark colored, almost blackish. Specimens of the xiresent species are sometimes found 

 in American herbaria bearing the name of P. Brodicei, a species having six siphons, 

 which has not as yet been detected with certainty on our coast. The P. Brodicei of 

 Bailey's List of United States Alga? is, according to Harvey, P. fibrillosa. 



Sect. III. Sijrfions more than four, corticating cells icanting. 



P. variegata Ag.; Phyc. Brit., PI. 155; Ann. Sci. Nat., Ser. 3, Yol. 

 XVI, PI. 6. 



Fronds purplish brown, densely tufted, four to ten inches high, fila- 

 ments setaceous and rigid below, capillary above, dichotomo-multifid, 

 the lower axils patent, branches above somewhat zigzag, elongated, 

 with alternately decompound, flaccid branchlets, siphons six in number, 

 cortications wanting, internodes not much longer than broad; antheridia 

 linear-oblong, mucronate ; cystocarps ovate, short-stalked. 



At the foot of wharves, on Zostcra, &e. 



