ACTINIA AND OTHER ACTINOID POLYPS. 25 
and smaller in the diameter of the disk to over a fout,— 
though commonly between half an inch and three inches. 
One species from the Paumotu Coral Archipelago in the 

PARACTIS RAPIFORMIS, EDW. 
Pacific, a colored figure of which is given in the Atlas of the 
Author’s Report on Zodphytes (Plate III.), had a diameter 
across its disk of fowsteen inches; and it was also one of the 
most beautiful in those seas, having multitudes of tentacles 
with carmine tips and yellowish bases, around the open centre, 
gathered into a number of large groups or lobes. 
With rare exceptions, Actiniz live attached to stones, 
shells, or the sea bottom, or are buried at. base in the sand or 
mud. The attached species have the power of locomotion, 
through the muscles of the base, but only with extreme slow- 
