Jaymi Heimbuch / Leaf Barnacle (Pollicipes polymerus) group, California Mussels (Mytilus californianus), and White Acorn Barnacles (Balanus glandula), Lincoln City, Oregon

Jaymi Heimbuch / Leaf Barnacle (Pollicipes polymerus) group at sunset, Yaquina Head Outstanding Natural Area, Newport, Oregon

Paul Williams / Ochre starfish (Pisaster ochraceus) Goose barnacles (Pollicipes polymerus) California mussel (Mytilus californianus) and Giant green anenome (Anthopleura xanthogrammica) in rock pool, Vancouver Island...

Paul Williams / Ochre starfish (Pisaster ochraceus), Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus) in rock pool, Vancouver Island, British Columbia, Canada, July.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Norbert Wu / Leaf Barnacle (Pollicipes polymerus), a colorful variation of the goose-neck barnacle found only in Nakwakto Rapids and a few other places, Vancouver Island, British Columbia, Canada

Norbert Wu / Leaf Barnacle (Pollicipes polymerus), a colorful variation of the goose-neck barnacle found only in Nakwakto Rapids and a few other places, Vancouver Island, British Columbia, Canada

GEORGETTE DOUWMA / Leaf barnacles {Pollicipes polymerus} attached to wave-swept boulders, between high and low tide lines, Washington, USA.

GEORGETTE DOUWMA / Close-up of Leaf barnacles {Pollicipes polymerus} Washington, USA.

GEORGETTE DOUWMA / Leaf barnacle {Pollicipes polymerus} attached to wave swept boulder, between high and low tide lines, Washington, USA

Mark Taylor / Goose Barnacles (Pollicipes polymerus) feeding, Pacific, USA. Cirri extended to catch prey.