Middle Cambrian eocrinoids from western North America

Generic affinities of Gogia Walcott, 1917, and Eocrinus Jaekel, 1918, are evaluated. Because of newly discovered morphological characters, it is proposed here that Eocrinus be suppressed as a subjective junior synonym of Gogia. The new species, G. spiralis and G. granulosa, are described; three other species, G. prolifica Walcott, G. multibrachiatus (Kirk), are redescribed; and the generic concept of Gogia is revised. Lectotypes are designated for G. prolifica and G. longidactylus, and casts of both are illustrated with photographs for the first time. Paleoecological data indicate that representatives of Gogia lived on a muddy substrate in a low-energy marine environment.