24, BRITISH MARINE ALG. 
growing on floating timber, and also on rocks, where its bright grass- 
green filaments, 3in. or 4in. long, are curved or twisted together in exten- 
sively interwoven masses. Under the microscope the endochrome at 
maturity presents a series of beautifully distinct lenticular or lens-shaped 
cells, which finally burst through the tubular envelope, and reproduce 
the species. Part of a magnified filament is represented at a, (Fig. 27) ; 
a ripe spore is escaping from the terminal cell. The genus Lyngbya was 
dedicated by Dr. Harvey to Hans Christian Lyngbye, a Danish naturalist, , 
and this species was named in honour of Captain Carmichael of Appin, in 
Scotland, who discovered it. Lyngbya majuscula, very well represented 
in Fig. 28, is the largest of this genus, and strongly resembles, except in 
colour, long tresses of curling hair. Collectors sometimes eall it “‘ Mer- 
maid’s hair.”” It usually grows on muddy rocks between tide marks, but 
the finest specimens are 
thrown up from deep 
water. The filaments, 
which are densely inter- 
woven, present, under 
the microscope, the 
appearance of a bundle 
of tiny snakes. The 
endochrome is of a dull 
green or sometimes in- 
clining to purple, and 
is composed of nume- 
rous closely appressed 
ring-shaped cells, but 
here and there inter- 
rupted by a line as if 
broken, and sometimes 
separated into distinct 
joints, as seen in the 
two portions of mag- 
nified filaments at 3}, 
Fig. 27. Lyngbya flacca is another not uncommon species, being found 
on Ceramium rubrum and other algz ; but the filaments are so extremely 
fine, that it is next to impossible to represent them satisfactorily in a 
drawing; however, enough has been said of the plants of this genus to 
call the attention of collectors to a class of interesting species, too fre- 
quently disregarded simply because they require microscopic examination 
for an appreciation of their beauties, or because they are unattractive as 
book specimens. 
The genus Calothria, or ‘‘ beautiful hair,’’ as its name literally signifies, 
contains some remarkably beautiful but very minute plants. The filaments 
of one of them, Calothriz semiplena, seen at a, (Fig. 29), when magnified, 
have a very singular appearance, the little tubes being, as it were, varie- 
Fie. 26. Lyngbya Carmichelit. 
