289 
RHODYMENIA PALMETTA, Var. NICHENSIS. 
By E. M. Hotmss, F.L.§. 
(Puate 240.) 
Tue seaweed which bears this name in Harvey’s ‘ Phycologia 
Britannica’ has hitherto been considered of somewhat uncertain 
affinity, owing to the fructification being imperfectly known and to 
the absence of any striking characteristic in the cellular structure 
of the frond. 
Duby, who first described it in the ‘ Botanicon Gallicum’ 
(ii., p. 942), named it Halymenia Niceensis. Agardh, in ‘ Alg. Mar. 
Medit. = — p- 1538, 1842, — it to Rhody erst Palmetta 
J. Ag., as var. 8. Niceensis, distinguished from the fai chiefly by 
the Eeyets ‘clone threads, in epote the apex of the frond 
frequently —— and which either dilate into new leaves or 
bear prolificatio 
This arr angement was followed by Harvey in the ‘ Phycologia 
Britannica.’ In that classical work he points out, however, that 
the plant bears a close resemblance to the var. B. of Phyllophora 
Brodiei J. Ag. siaectmrtee ea oe J. Ag,), but that it always 
springs from decumbent —— He adds that, while Mediterranean 
es have usually a qui te simple | prolonged at the os 
0 a cirrhous appendage, Briti sh spec S$ are more c 
fotked, and their apices, though sikooniaced: are aula ree 
into the characteristic appendages 
Kiitzing figures it in his “Tab. Phye.’ xviii. t. 96, as Sphero- 
coccus Nic is, and his illustration shows eystocarpic fruit near 
some measure the position rightly assigned to the plant, since if 
the tetraspores were arranged in ot it would apparently 
belong to the genus Phyllophora. Owing to the great similarity in 
the shape and structure of the frond to that of Phyllophora palmet- 
toides, the two plants probably often pass the one for the other when 
the terminal cirrhi are absent and the fronds are collected without 
the root, which in the latter is a spreading dise and in the former 
myself ar Sa aig in April last, I was so fortunate as to find 
tetraspores in the terminal filiform appendages. These “sate 
ce as in P, palmettoides. The cystocarps were unfortunatel 
en: in drying that their contents were lost, but, being sea 
ar the base of the frond instead of towa rds the apex, as in 
Palmetta, the plant under consideration may, I think, be faitly 
JournnaL or Borany.—Von. 21. ‘TOcrwuns, 1883.] 
