A recently discovered new species of diploglossine lizard is described from west-central Panama. The distinctiveness of the nominal genera Celestus and Diploglossus is confirmed; the new form represents the southernmost record for the genus Celestus. A summary of selected characteristics and general distribution is presented for all recent species of diploglossines, including members of the Antillean genera Saurisia and Wetmorea and the South American genus Ophiodes. A systematic key to mainland members of the genus Celestus is provided.