Of the eleven Norfolk species of autolytoid, three were successfully used for feeding trials; all were found to feed exclusively on hydroid polyps under laboratory conditions, using the method of feeding described by Okada (1928) and others. Field observations confirm that, in summer, hydroid colonies are the normal habitat of these worms, but that they seek other (as yet unknown) sources of food in winter when the hydroid have died down. Further aspects of food selection by autolytoids arc discussed.