Ser. RuoposrprerMeEx. Fam. Rhodomelec. 
Pirate CCXCIII. 
POLYSIPHONIA ELONGATA, Grev. 
(Lor description, see last page.) 
nnn nnn nn nnnnens> 
In last plate we have figured the ordinary form of P. elongata 
(Lobster-horns) in plants of the first season; and our present 
plate represents a plant of the second year’s growth. In winter 
the tips of the branches and ramuli of the first year fall away, 
leaving a stunted and broken frond, very unsightly and often 
distorted : this constitutes Ceramium brachygonium of Lyngbye. 
Karly in spring, new growth commences ;—the broken branches 
put forth vigorous shoots, ending in broad pencils of crimson 
ramuli, which in a short time clothe the whole upper part of the 
frond in the rich costume which we have endeavoured here to por- 
tray. ‘These different aspects of the species are puzzling to a 
young observer, who is apt to take a plant of the second year 
for a different species ;—but were these the only difficulties con- 
nected with P. elongata, a little practice would soon enable the 
young botanist to surmount them :—for similar changes from 
winter to summer occur in many other Alge, as Rhodomela 
subfusca, Desmarestia aculeata, &c., and are no other than what 
continually pass under our eye in the case of land plants whose 
leaves are deciduous. 
But unfortunately, P. elongata varies in other respects, as may 
be inferred from the several synonyms which I have enumerated, 
a list that would probably be extended had I the advantage of 
consulting authentic specimens of several other reputed species. 
The form called P. Ruchingeri, originally found in the Adriatic, 
is common enough on our coast, and differs from ordinary 
P. elongata in being much more slender, of less cartilaginous 
substance, and especially in having longer articulations. I have 
examined authentic specimens communicated by Prof. J. Agardh, 
VOL. III. P 
