Genus Callorhinus is a genus of mammals that includes two species of fur seals, northern fur seals and Guadalupe fur seals. Other synonyms for the genus Callorhinus include Arctocephalus ursinus, Arctocephalus callorhynchus, and Callorhinus ursinus. The northern fur seal, once hunted for its valuable fur, is now a protected species, with populations ranging from the Bering Sea to California. The Guadalupe fur seal, on the other hand, is one of the rarest pinnipeds in the world, with a population of only a few thousand individuals. Both species are characterized by their thick fur, streamlined bodies, and excellent swimming abilities.