1£0 POPULAR HISTORY OF THE AQUARIUM. 



and habit, that I have thought it might prove interesting to 

 transmit this short notice/' 



The Polype was afterwards described as Edwardsia. It 

 is a free, worm-shaped Actinia, which constructs a leathery 

 tube to live in. The cylindrical body terminates obtusely 

 at one end, and in a flower-like disc at the other. In the 

 centre of the disc is a circular mouth surrounded by nume- 

 rous short tentacula springing from its inner margin. 

 Eound the outside of the disc is another row of larger ten- 

 tacula, very much like those of an ordinary Actinia. The 

 tentacles are never withdrawn into the mouth, but are often 

 reduced by contraction to very small dimensions. Mr. 

 Porbes observes, that the body can be greatly lengthened 

 so as to assume the form of a tapering worm, or Holothu- 

 ria ; and that it is protected by a membranous tube, which 

 is itself strengthened by an incrustation of gravel and shells 

 in the manner of a Terehella. It can move freely up and 

 down in this tube, and sometimes, leaving it altogether, 

 construct another. When out of the tube, our Edioard- 

 sia crawls along very much in the manner of a worm, but 

 with the disc expanded, and perhaps using the tentacles at 

 its margin as organs of locomotion. It soon secretes a 

 quantity of glairy matter, to which shells and sand adhere. 



