Detail of the oral discs of Phymanthus pinnulatus, external morphology A top view of discal tentacles present on a live individual, arranged as radial rows between intermesenterial spaces, extending from the mouth towards the region of the marginal tentacles (ZRC.CNI.1361) B side view of discal tentacles of a living specimen; note the low and reduced elevation of tentacles (ZRC.CNI.1046) C faint and reduced radial rows of discal tentacles (arrowed) present on a recent, formalin-fixed specimen (ZRC.CNI.1345) D very reduced and barely noticeable remnants of discal tentacles (arrowed) present on the holotype (NRS76); note that this specimen was preserved before 1877. Abbreviations: m, mesenteries; mt, marginal tentacles. Photographs by NWL Yap.