LIST OF THE SEA- WEEDS OR MARINE ALG.E, ETC. 287 



31. P. Olneyl, Hakv. Wood's Hole, (common,) Waquoit. 



32. P. Hanriji, Bail. Very commou on eel-grass; the bottom of the 



small harbor at Wood's Hole sometimes covered with this plant 

 after a southerly wind; washed np so abundantly at Southold, 

 Long Island, in the autumn, as to be used for manure. It must 

 be confessed that this species is not well defined passing on 

 the one hand, into P. Olneyi, and, on the other, into P. Harvey I 

 var. arietina, Harv., which seems to me to be lull as clearly a 

 distinct species as P. Hnrveyi itself. Bailey so regarded it. This 

 plant is called on Long Island " nigger-hair ;" at Wood's Hole, 

 "dough-balls.'' I have fine specimens a foot in diameter 

 whereas in var. arietina the tufts are seldom over two inches in 

 diameter. This variety is very common on the south side of 

 Lynn Beach on eel-grass. 



33. P. subtlUssima, Mont. Seekonk Eiver, (S. T. Olney.) 



34. P. elongata, Grev. Common at Gay Head, and floating near 



Meuimshi Bight. I did not collect this species until August, 

 Avhen nuxny of the terminal fibrils had fallen off, leaving the 

 ramuli rather bare. Also at Lynn Beach, but neither so luxu- 

 riant nor abundant. 



35. F.Jibrillosa, Grev. Greenport. 



36. P. vtolacea, Grev. Orient Point, Gay Head, and Menimshi. 



Not uncommon. 



37. P. rariefjata, Aa. Very common in all warm, shallow water, on 



piers, in company with Solieria chordaUs. Wood's Hole, Wee- 

 pecket Islands, Greenport, Orient, Xew Haven, (Professor 

 Eaton.) 



38. P. atrorubescens, Grev. Gay Head and Meuimshi Bight, floating 



with P. elongata and violacea. Not very common. Some speci- 

 mens collected in July are a foot long, and the branches are 

 covered with subulate ramuli, while others, gathered in Sep- 

 tember, are not more than two or three inches long, nearly des- 

 titute of lateral ramuli, and look like black horse-hair. 

 30. P. nigrcscens, Grev. Wood's Hole, Gay Head, Orient. Yar. 

 fucoidcs common on fucus at low-water mark at Weepecket 

 Islands, New Haven, (Professor Eaton,) Gay Head. Dredged 

 in ten fathoms near No Mans Land. 



40. P.fastigiata, Grev. Notwithstanding the commou occurrence of 



Fucus nodosus, on which this is generally parasitic, I have found 

 ^t Wood's Hole only a few specimens of this species, and those 

 faded and greenish. New Haven, (Professor Eaton.) 



41. Basya elegans, Ag. Very common from New York to Nantucket, 



being one of the most striking and abundant rhodosperms dur- 

 ing the latter part of August and September. Washed ashore 

 at Gay Head. 



