§60. Mute Stems

The following irregularities require notice:—

a. Greek neuters with nominative singular in -a (as poēma) frequently end in -īs in the dative and ablative plural, and rarely in -ōrum in the genitive plural; as, poēmatīs (for poēmatibus), poēmatōrum (for poēmatum).

b. A number of monosyllabic nouns with mute stems want the genitive plural (like cor). See § 103. g. 2.