G. AMATHIA. 69 



HORNED. 



2. Amatfiia coniuta. 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 uuUateralis. Branches curved in- 

 wardly ; groups of the cells almost all touching, and 

 placed on the same side. 



Mediterranean. 



ALTERNATE. 



4. Amathia altemata. 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 ceils united and 

 forming one group, projecting, and spirally surround- 

 iflor the stems and branches. 



American seas. 



spiral. 



G. 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. 



