found in degree, form the striking mark of the species. Yet 
these ramuli are not noticed by Agardh in the description which 
he has given, in his Species Algarum. It would, therefore, be 
very questionable whether our plant and his were identical had not 
Mr. J. G. Agardh seen and examined specimens of the British 
plant, and pronounced them to be similar to those described by 
his father. But for this evidence, which I suppose is conclusive, 
I should have regarded the plant now described as a novelty ; 
and, indeed, until the specimens had been submitted to Mr. 
Agardh, I did so regard it, and had intended to dedicate it to its 
estimable discoverer in this country, by the name C. Radfsiz. 
Should future observations prove that the plant of the elder 
Agardh is really different (as I suspect may be the case) I hope 
that the name La/fsiz may be retained for our British plant. 
I have seen no specimens but those gathered by Mr. Ralfs in 
1838 ;, nor have I heard of the species having been met with by 
any one else, except Mr. Berkeley, on the British coast. 
Mig. 1. CALLITHAMNION barbatum ; tuft :—of the natural size. 2. Portion of 
a filament. 3. Apex of a branch, with tetraspores. 4. Ramulus and 
tetraspores :—all more or less highly magnified. 
