The Rev. Z. M. Hamilton, of Bressay, Zetland, has ascertained that this beautiful zoophyte feeds upon the young Littorina littorea. In a letter to Dr.Neill of the 3rd of March, he writes, " I discovered that it feeds on small wilks, which it, by means of its arms and feelers, puts into its stomach, so many even as four or five at a time, and when the meat is fully extracted the shells are rejected."
In a subsequent communication (20th of March) to Dr. Neill, Mr. Hamilton says, — " With regard to the food which this creature seems so much to enjoy, that there may be no mistake, I enclose the shell of a wilk (a small specimen of Littorina littorea) which I gave it two days ago, and which was today rejected in the empty state it now is, " It is most interesting to watch the animal's movements ; every day it appears in a different form, and developes new beauties. I almost think it is getting tame, for it does not now shrink from observation as it did at first, and readily clutches upon its food. When more than one wilk is given to it, it retains, by means of its feelers, those it cannot at once consume, — thus making them wait their turn, which comes so soon as the first taken are rejected. I once saw four or five wilks, of the size of the shell now sent, in its stomach at one time." — George Johnston.
Ref: Annals And Magazine of Natural History - Volume 2. 1848.
Article refers to Lucernaria quadricornis.