Page:The aquarium - an unveiling of the wonders of the deep sea.djvu/239

192 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 intrusion on a ground already occupied. Flat stones, but more commonly large bivalve shells, such as oysters, pectens, and pinnæ, 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 Actiniæ. I have now in my Aquarium several specimens of large size, which I displaced 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 manifested 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.