192 ITS LOCOMOTIVE POWERS. 



Yet one now and then sees an individual of quite 

 another colour in the group ; a circumstance to be 

 accounted for on the supposition of an accidental in- 

 trusion on a ground already occupied. Plat stones, 

 but more commonly large bivalve shells, such as 

 oysters, pectens,, and pinnee, are the sites selected for 

 the colonies of this Actinia. 



Dr. Johnston's statement, that " A. dianthus is a 

 permanently attached species, and cannot be removed 

 from its site without organic injury to the base," is 

 not confirmed by my experience. I find that it can 

 be removed by the fingers without any difficulty, and 

 that it adheres again to a fresh place with the same 

 readiness as other Actinim. I have now in my Aqua- 

 rium several specimens of large size, which I dis- 

 placed in the usual manner, from their oyster- shells, 

 by shoving them off carefully with the back of my 

 finger-nails, and which I merely set down on the 

 pieces of rock-work. I found them firmly refixed in 

 the course of an hour or two, and they have manifest- 

 ed no disposition to unsettle themselves since, though 

 they have been there for several weeks. On the 

 other hand, one which I had put in with the shell to 

 which it was affixed, presently crawled spontaneously 

 from his original site, and took up a new abode on 

 the rock-work. The change was effected by the 

 ordinary gliding.movement of the base, and was not 

 particularly slow. Indeed, I can state distinctly that 

 dianthus crawls as freely as any other species. 



The rank odour noticed in A. parasitica is very 

 powerful and enduring in this species also, as it is in 

 A. crassicornis. • 



