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RHODOSPERME. 187 
ramuli, a bi-lobed favella being suspended from a trifid ramulus. Tetra- 
spores, when present, are attached to the sides of these little ramuli ; 
they are very minute, roundish, and produced in twos or threes, and 
Sometimes in clusters. The colour of the living plant is a pinky red, 
turning a pale reddish brown in drying. It is said to be perennial, and is 
in perfection from July to September. 
The beautiful and extensive Order Ceramiacee contains many of the 
most delicate and attractive of the British red seaweeds. The structure, 
even in the most compound forms of these plants, is exceedingly simple, 
being for the most part strings of cylindrical cells, more or less 
branched, the little cells or joints each growing out from the tip of the 
one below it, the branches being formed by cells arising, or budding, 
Fig. 173. (a) Terminal branch of Spyridia filamentosa; (b) Portion of the same 
with bi-lobed favella, magnified. 
as it were, from the upper sides of the mature or previously formed 
articulations. In the larger and more compound forms, the stems and 
some of the principai branches are coated or supplied internally with 
closely packed longitudinal filaments, which traverse the fronds and 
render those portions of the plants nearly opaque; but even in these 
apparently more highly organised structures, a very slight examination 
will reveal the original articulated filament, which is the charac- 
teristic structure of most of the species of this interesting tribe of 
marine alge. 
The name of this Order is from the Greek for a pitcher, in reference to 
the form of the fruit, which is much more characteristic of the Ceramidia 
of the Polysiphonie than of any of the spore-vessels of the Ceramiacee, 
which are berry-like, but not in any instance pitcher shaped. However, 
