G. AMATHIA. 
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HORNED. 
2. Amathia cornuta . The largest cell of each 
group has a free unattached border, garnished with 
two setaceous appendages. — Plate 4. fig. 1. a. B. 
On the fucus of Australasia. 
UNILATERAL. 
3. Amathia unilateralism Branches curved in- 
wardly ; groups of the cells almost all touching, and 
placed on the same side. 
Mediterranean. 
alternate. 
4. Amathia alternata. Very branchy; groups 
of cells very long, placed alternately, and very close 
upon the branches; cells numerous, and of nearly 
the same size. 
American seas. 
convoluted. 
5. Amathia convoluta. All the cells united and 
forming one group, projecting, and spirally surround- 
ing the stems and branches. 
American seas. 
SPIRAL. 
6. Amathia spiralis. Branching and dichotomous ; 
cells forming only one group, spirally surround- 
ing a centre, and adhering by their inner surface. 
—Plate 4. fig. 2. a. B. 
Australasian seas. 
