D defs.my
Entry 1 sense Webster, 1913

Cornu Ammonis

/(ăm*mō"nĭs)/ · Cor·nu Am·mo·nis · IPA
01 A fossil shell, curved like a ram's horn; an obsolete name for an ammonite.
pl. ‖Cornua Ammonis
  1. 1.
    A fossil shell, curved like a ram's horn; an obsolete name for an ammonite.(Paleon.)