by Agardh, I published it as new, in the ‘ Annals of Nat. 
History for 1844, under the name of C. Polleafenii, as a just 
tribute to its acute discoverer. At that time I had no suspicion 
that it could be the C. floccosum of Agardh, because the character 
he gives ‘“‘ramellis oppositis ascendenti-patentibus swrsum pecti- 
nato-pinnatis, pinnis simpliciusculis,’ by no means answers to the 
present individual, and agrees very well with a common variety 
of C. Plumula. Yorming my judgment on the words “ sursum 
pectinato-pinnatis ;’ as well as on Agardh’s reference to Dillwyn’s 
Plate 50. f. A, and on the note appended to his description, 
“Hine heee icon semper nobis dubia fuit, usque dum Hookerus 
specimen Conferve Plumule, Dillw. misit, quod omnia explicavit, 
et nobis persuasit, dua individua diverse speciei picta esse ;” I 
could not believe otherwise than that his C.floccosum was founded 
on a bad specimen of C. Plumula, for I knew that Sir W. J. 
Hooker could never have sent Agardh a specimen of my C. Pol- 
lexfenii, which did not exist in his Herbarium, until Dr. Dickie 
communicated it in 1844; and still less could it have been the 
plant intended by Dillwyn’s figure. Were there no other 
grounds, therefore, for upholding Agardh’s C. floccosum, than the 
description he has given of it, that species must be erased, and 
its synonymes transferred to C. Plumula. But the real founda- 
tion of C. floccosum rests, on the figure in ‘ Flora Danica,’ and 
the description given by Lyngbye, in his excellent work, above 
quoted. My error consisted im having omitted to refer to 
that figure and description; for though the figure is not very 
accurate, yet it certainly is more characteristic of our plant than 
of C. Plumula; while the description given by Lyngbye, and 
which was taken from an authentic specimen of the plant figured 
in ‘ Flora Danica,’ answers in all respects to my C. Polleaxfenii. 
I am compelled, therefore, to restore the specific name, under 
which this species was first published. 
C. floccosum would appear to be peculiarly a northern plant, 
confined, so far as we know, to the coasts of Norway, and the 
north of Scotland,—in both which countries it is of extreme rarity. 
Fig. 1. CAaLLITHAMNION FLOCCOsUM ;—of the natural size. 2, A branch :-— 
magnified. 3. Portion of the same. 4. Ramuli with tetraspores. 5. A 
tetraspore :—highly magnified. 
