There is a peculiar rigidity and wiryness in the frond of this 
plant, which at once distinguishes it from any other British 
Alga with which it can be confounded: and, when dry, the 
glossy surface is equally strikmg. It often occurs in large 
bundles, very much tangled together, and then looks like a mass 
of rigid dark-purple bristles. 
I have never seen fruit perfectly ripe on any specimens that 
I have examined. The wart-like receptacles of fruit are common 
enough, but they seem to come to perfection but seldom. This 
is very different from the habit of @. Grifithsie, in whose gongri 
tetraspores are always found, and are some of the most beautiful 
of marine microscopic objects. 
G. plicatus, in its geographical distribution, is almost a 
cosmopolite. 
Fig. 1. GyMNoGoNnGRUS PLICATUS :—the natural size. 2. Magnified portion 
of a branch, bearing tubercles. 3. Transverse section of branch and 
tubercle. 4. A small segment of the same :—wmore highly magnified. 
d P— ee 
oe Se Ganga a © 
