LATIN DICTIONARYLexicon Latīnum
Allen & Greenough · Part First — Words and Forms › THIRD DECLENSION (CONSONANT AND i-STEMS)

§78. Summary of i-Stems

The following have -um (not -ium) in the genitive plural:

  • Always, canis, iuvenis,1 ambāgēs, mare (once only, otherwise wanting), volucris; regularly, sēdēs, vātēs.
  • Sometimes, apis, caedēs, clādēs, mēnsis, struēs, subolēs.
  • Very rarely,—patrials in -ās, -ātis; -īs, -ītis; as, Arpīnās, Arpīnātum, Samnīs,Samnītum.

J. H. Allen and J. B. Greenough, New Latin Grammar (Boston: Ginn, 1903). Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities.