Abstract
The family Seguenziidae, including the genus Adeuomphalus, of the northeast Pacific are here revised. Seguenzia megaloconcha Rokop, 1972 is here synonymized under S. cervola Dall, 1919, S. quinni McLean, 1985 is here synonymized under S. gioviae Dall, 1919, S. catalina Dall, 1919 and S. certoma Dall, 1919 are synonymized under S. stephanica Dall, 1908. They represent either growth stages of one another, or are based on insignificant minor sculptural differences. A short commentary on the contraproductive proliferation of taxonomic data portals and the need for a single resource akin to GenBank is given.