PLUMULARIA. 1538 
“This very rare coralline grows to the height of ten or 
twelve inches. ‘The root, or first beginning, consists of an 
irregular tuft of extremely small tubes, appearing like a 
piece of sponge to the naked eye. Several of these little 
tubes rising together, and uniting in close contact, become 
a stalk, which appears in the microscope curiously chan- 
neled and indented.” (H/is.) The stalk is generally simple. 
In the figures by Ellis there is one in which the stalk is 
once divided near the base. In all our specimens the stalks 
have been simple, undivided, but composed of a number of 
tubes, which gives it, when dry, a furrowed appearance. “In 
each of these furrows there is a row of small holes with a 
raised brim, as if punctures had been made by an instrument 
pushed from within. The holes are close-set, and regular 
in their size, form, and in the distances between them. 
No probable conjecture of the use of these has been made.”’ 
(Dr. Johnston.) 
In more respects than one, our specimens of this beau- 
tiful coralline—this ‘‘ alma marina,’ as some of the old 
naturalists call it—were singularly fine. The usual height 
is said to be six inches, Ellis mentions ten or twelve. One 
specimen I got in Lamlash Bay measured eighteen inches 
from the base to the tip of the plume. One of its general 
