Another alternate name is Pacific gull, though it also applies to a Southern Hemisphere species, L. pacificus.

The genus name is from Latin larus, which appears to have referred to a gull or other large seabird.

The specific schistisagus is from Neo-Latin schistus, "slate", and Latin sagus, "cloak".

Individuals have strayed to various places throughout North America, including New England and Texas.

The inner webs to primaries are pale grey, and the mid-primaries have long grey tongues tipped with large white crescents, forming a "string of pearls" pattern connecting to the broad white trailing edge of the secondaries.