Engraving of the horned viper of Egypt, possibly from a drawing by Ellis. Engraving by James Gwin. Sent by John Ellis in his letter to Carl Linnaeus, 5 December 1766 n.s., "The Linnaean correspondence", linnaeus.c18.net, letter L3837.
Published in Ellis, J. 1766. A Letter from John Ellis, Esq; F. R. S. to the President, on the Coluber Cerastes, or Horned Viper of Egypt. "Philosophical Transactions of the Royal Society". 56, 287-290.