174 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Massachusetts Bay, Harvey; common from Cape God to the West 

 Indies; Europe. 



A beautiful summer species, forming large purple tufts on wood-work and various 

 substances a short distance below low- water mark in warm, skeltered waters. The 

 lower branches are rigid and widely spreading, but the tips are byssoid and collapse 

 on being removed from the water. When mounted on paper small specimens have a 

 slight resemblance to P. Olneyi, but the species is coarser, and the siphons are six in- 

 stead of four in number. 



P. parasitica, Grev. j Phyc. Brit., PL 147. 



Fronds dark brownish red, one to three inches high, filaments com- 

 pressed, decompound-pinnate, branches alternate, distichous, 2-3 pin- 

 nate, ultimate divisions erecto-patent, subulate, acute, internodes about 

 as long as broad, siphons 8-9, cortications wanting ; cystocarps ovate, 

 on short stalks. 



Providence, E. I., Harvey; Europe; California. 



A small species, said to have been collected by Mr. Hooper on the authority of Har- 

 vey. It differs from our other species in the compressed frond and uniformly distich- 

 ous arrangement of the branches. In aspect it looks more like a fine Ftilota than a 

 Polysiphonia. In drying it does not adhere well to paper. In California the species 

 is rather common, especially the large variety dendraidea. 



P. ATRORUBESCENS ; Grev. ; Phyc. Brit., PI. 172. 



Fronds tufted, dark red, two to twelve inches long, filaments setace- 

 ous, rather rigid, branches long, erect, alternately decompound, with 

 scattered, simple or virgately tufted branchlets, which taper at the 

 base and apex, siphons usually 12, spirally twisted, articulations gen- 

 erally 2-3 times as long as broad; antheridia oval, terminal; cystocarps 

 broadly ovate, sessile. 



In deep water and washed ashore. 



Gloucester, Mrs. Davis; Gay Head, Mass., W. G. F.; Fisher's Island, 



Prof. Eaton; Orient, L. I., Miss Booth; Noank, W. G. F.; Little Comp- 



ton, E. I., and Long Branch, N. J., Harvey; Europe. 



One of our less common epecies, recognized by the number of siphons, which are 

 usually spirally twisted, and by the long branches, which bear small branchlets that 

 taper at both extremities. Late in the season one finds denuded, rigid specimens, 

 which bear little resemblance to the form found early in the season. It does not adhere 

 well to paper in drying, and becomes quite black in the herbarium. 



P. nigrescens, Grev. 



Fronds dark brown, three to twelve inches long, rigid below, becom- 

 ing flaccid and much divided above, branches alternate, decompound- 

 pinnate, ultimate branches subulate, siphons 12-16, articulations about 

 1^-3 times as long as broad ; antheridia lanceolate, mucronate; cysto- 

 carps ovate, subsessile. 



