without laceration. Its colours are sometimes much brighter 
than at others, especially (as observed by Dr. Drummond) in 
places where it is exposed to the dripping of fresh water. 
The affinity of this obscure plant is rather doubtful, and I am 
by no means satisfied with the position which I have now 
assigned to it, next the Nwu/lipores. It differs from those vege- 
tables in wanting the lime which forms so remarkable a portion 
of their solid contents; but its cellular structure is not very 
unlike that of a Vu/lipore, and there is a near resemblance in the 
fructification. The cells composing the frond in the Nullipores 
or Melobesia, are longer and narrower than those of the Hi/den- 
brandtia, but arranged in an order neatly similar. 
Kiitzing (Phyc. Gen. p. 384) makes three species; H. san- 
guinea, H. rosea, and H. Nardi, which to judge by the author’s 
diagnoses, differ from each other merely in colour ;—the first 
being “ferrugineo-sanguinea,’ the second “ coccineo-rosea,” and 
the third “ /utescenti-fusca, siccitate nigrescens.” This last may 
possibly be our Ra/fsia. 
Tam not acquainted with the writings of the botanist to whom 
this genus is dedicated. 
Fig. 1. HIinpDENBRANDTIA RUBRA, on a stone :—natural size. 2. Portion of 
the frond, with dise-like depressions. 3. Section of the same, cut through 
a conceptacle. 4. Tetraspores :—all magnified. 
