Axial Bifurcation and Duplication in Snakes. Part VIII. Specimens Deposited in or Affiliated with the Natural History Museum of Paris (MNHN)

A review of the dicephalic (two-headed) snakes in the Natural History Museum of Paris (MNHN) reveals that 16 specimens have been present or catalogued into the various collections (MHNH-RA, MNHN-AC, and Teratological Collection) over the years. Only seven specimens have been located in the collections but some of the nine missing specimens may be present but not yet found. The 16 MNHN specimens are described based on available information. More details are provided for the seven extant specimens in the collections, including photographs, radiographs, and the first description of the internal anatomy of dicephalic Elaphe schrenckii , Natrix maura , and Montivipera xanthina .