62 
CLASS I. — ORDER I. 
FEATHERY. 
12. Crisia plumosa. Stem very branching, up- 
right and dichotomous ; cells unilateral, alternate, and 
terminated at the summit by a point. 
European seas. 
Q, C/r J 

MENIPEA. 
Plant-like Polypidom; branching and articu- 
lated ; cells having their opening on the same side, 
and many united together in concatenated masses. 
The general appearance of the Menipeas, and the 
singular form of their cells, give them a distinct and 
peculiar character. Their branches bend in the form of 
plumes, and instead of straightening, curve still more 
when put into water. Their cells, more or less nume- 
rous, are placed in masses of a triangular form, and 
linked one to the other, having their opening always 
on the same side and in parallel lines ; there are ge- 
nerally three placed on the larger part of the wedge, 
two on the second line, and then a single one termina- 
ting this reversed pyramid ; sometimes there are only 
two rows of cells, and even a single one placed at 
each articulation. The Menipeas bifurcate at each 
articulated mass. 
Their substance appears more calcareous than 
membranous or horny ; they are very friable, and 
preserved with difficulty. 
Their colour is a yellowish white, bordering on 
grey. 
