A new Eocene species of Hydroides (Polychaeta, Serpulidae) from the Cowlitz Formation, Lewis County, Washington State, USA

Fossil calcareous serpulid tubes found in the middle Eocene Cowlitz Formation, Lewis County, Washington State, have not previously received detailed study. Some distinctive tubes have been found that were epibionts attached to gastropod shells and represent a new species of Hydroides . Hydroides has a limited Paleogene fossil record. The new species from Washington, Hydroides engi , is the first confirmed Eocene record for the genus. One previously named species, H. primitiva Howell, 1948, from Paleocene rocks in New Jersey is a nomen dubium.