[Taxacom] Zoantharian?

[Juan Francisco Araya]

Dear Colleagues:

I wonder if anybody can help me with an identification for an organism; I
think it may be a zoantharian, but I am not sure.
Images of these specimens are depicted at the next link:

https://www.flickr.com/photos/drilus/22731793885/

These are attached to an octocoral (Swiftia?), collected as bycatch off
northern Chile (2000 m depth).
Any hints on its identity will be very appreciated.

Best regards,

Juan Francisco.