LIST OF THE SEA-WEEDS OR MARINE ALG.E, ETC. 291 



G3. C. rosea, {Chrys'menia, Fhyc. Britf.j) Harv. This rare and beau- 

 tiful alga I have found only by dredging in the region of the 

 Devil's Back, Gay Head, in eight or ten fathoms. The tetra- 

 spores only were found. 



SPYRlDIACEiE. 



64. Sjyyridia filament^sa, Harv. Common on eel-grass at Wood's 



Hole, Waquoit, Weepecket, and Greenport. 



CERA3IIACE^. 



65. Ceramium riibrum^ AG. Common everywhere. 



(jQ. CdiajyMnnnij'RoTB.. Common and luxuriant on eel-grass. Wood's 

 Hole, Weepecket, Edgartown. 



67. C. fastigiatim, Hart. Common on eel-grass in August and Sep- 

 tember at Wood's Hole, Weepecket, Newport, Orient, and 

 Greenport. 



C)S. C. araclinoideum, (?) AG. Wood's Hole, Orient Point. There 

 grows in abundance on faci, at Wood's Hole, a Ceramium 

 without fruit of either kind in September. It grows in long 

 patches on the stems of fuci near low- water mark. The fila- 

 ments are rather robust, not more than an inch long, scarcely 

 branching and forcipate at the tip. The internodes are di- 

 aphanous, and I am not certain that it is not a young state of 

 C. diaplianum. At any rate I will not confuse an already suffi- 

 ciently subdivided genus by adding a doubtful species. 



69. Ptilota eJegans, Bonnem. Common between Gay Head and Ko 



Mans Land, Xewi)ort. Wherever found, abundant. 



70. Griffitlisia corallina, AG. This charming plant is not uncommon 



during July in Buzzard's Bay, Wood's Hole, and Weepecket 

 Islands ; at the latter station I have seen the water full of it 

 Ysiv. glohifera 1 have found only on the Government Wharf, 

 Wood's Hole, and once or twice in Buzzard's Bay. It is coarser 

 in color and texture, and is not so easily dried on paper as the 

 ordinary form. If merely a variety, it seems to owe its form to 

 its exposed place of growth. 



71. Callithamnion ietragonum^ AG. Wood's Hole, Martha's Yineyard, 



Newport. Common on the larger algie and wood-work just 

 below low-water mark. 



72. C. Baileyij Hary. Not to be distinguished, in my opinion, from 



C. tetragonum, except by being less robust and somewhat more 

 compoundly branched. It seems to me to be merely a variety 

 grown early in the season while the water is warm. 



73. C. Borreri, Ag. Greeuport, Wood's Hole. My specimens are 



softer than European, and seem too near C, poly sper mum. 



