soft body part shell capitulum 2019-10-05T09:15:37Z BTO:0006314 BrendaTissueOBO Marion Pedunculate, goose or goose-neck barnacles have a flexible, muscular stalk, known as the peduncle, which supports the main body known as the capitulum. In Pollicipes pollicipes the capitulum is triangular in nature and white-grey in colour. A number of plates of different sizes protect the capitulum, increasing to over 100 in number with age. The plates may reach up to 0.5 mm in length. Six pairs of thin, feather-like cirri can be seen to arise from within the mantle cavity and are used for feeding. mussel capitulum