1 
3 
: 
À 
: 
à 
3 
ALGÆ ANTARCTICA, 271 
Allied to S. Hookeri, but smaller, and with more patent rami- 
fication. 
52. Ptilota Harveyi, Hook. fil. ; caule compresso cartilagineo 
anguste lineari inarticulato furcato vel inordinate ramoso, 
ramis distichis pinnatim decomposito-ramosis, majoribus 
et minoribus costa articulata percursis pectinato-pinnulatis, 
pinnulis creberrimis abbreviatis simplicibus articulatis mo- 
nosiphoniis subulatis oppositis, articulis pinnularum qua- 
dratis, favellis ad apices ramulorum sitis, ramulis pinnatis 
involucratis spherosporis ad apices pinnularum aggregatis 
nudis bréve pedicellatis. 
var. f. pectinata ; pinnulis subdistantibus. 
Has. Cape Horn and the Falkland Islands, abundant.— 
var. (3. Cape Horn. 
Frond 8-12 inches long and nearly as broad in the spread- 
ing of the branches. Stem filiform, 4 a line in diameter, 
nearly of equal breadth throughout, irregularly forked, dicho- 
tomous, or very much branched in a manner between dicho- 
tomous and pinnate; the lesser branches more regularly 
pinnate or bipinnate; every part of the frond, but especially 
the younger portions, beautifully pectinated with opposite 
jointed ramuli, of a line in length. "These ramuli are simple, 
and single-tubed, like those of a Callithamnion. The var. 6 
only differs from the common form in having the ramuli more 
distant. The species to which this is most nearly allied is 
undoubtedly P. plumosa of the Northern Hemisphere, whose 
variety 8 (which Kutzing has erected into a species, P. ele- 
gans, Kg.) bears articulated ramuli. Our plantis, however, 
much larger than this variety, more rigid, and the ramuli are 
of much greater diameter. Compared together under the 
microscope, they are seen to be abundantly different. 
53. Callithamnion simile, nobis; fronde subsolitaria rigidius- 
cula ramosissima, ramis alternis v. subdichotomis articulatis 
aveniis, ramulis brevissimis oppositis distichis horizontali« 
bus crassis sursum pectinatis è quoque ramorum articulo 
porrectis, pinnulis robustis simplicibus v. ramosis, arti- 
