Historic importance of some aspects of research by O. Wilford Olsen on hookworms (Uncinaria lucasi) in northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumatopias jubatus) in 1951 on St. Paul Island, Alaska.

The purpose of this paper is to disseminate, more widely, certain historically important aspects of research by O. Wilford Olsen on hookworms (Uncinaria lucasi) in northern fur seals (Callorhinus ursinus) and Steller sea lions (Eumatopias jubatus) in 1951 on St. Paul Island, Alaska. Highly meaningful facets of the research were recorded only in a report with limited availability by Olsen in 1952. Portions of his research presented here include measurements of hookworm free-living infective third-stage larvae (L3) and adults, photographs of bursae, and the conclusion that the species of hookworms (U. lucasi) is probably the same in both pinniped hosts. This information is especially important because very little has been published on taxonomy of hookworms in E. jubatus.