- Researches In Prehistoric And Protohistoric Comparative Philology, Mythology, And Archaeology: In Connection With The Origin Of Culture In America And The Accad Or Sumerian Families
- A Short Handbook of the Comparative Philology of the English, Anglo-Saxon, Frisian, Flemish or Dutch, Low or Platt Dutch, High Dutch or German, ... French, Spanish, and Portuguese Tongues
- The Early History of the Mediterranean Populations, &c., in Their Migrations and Settlements: Illustrated from Autonomous Coins, Gems, Inscriptions, &c
- Serpent and Siva Worship and Mythology, in Central America, Africa, and Asia. And The Origin of Serpent Worship. Two Treatises
- The Khita and Khita-Peruvian Epoch