bacterium bacteria
beau beaux
cherub cherubim (or cherubs)
crisis crises
curriculum curricula
datum data
genus (meaning "class") genera
genius {geniuses (persons or great ability)
{genii (spirits)
hypothesis hypotheses
oasis oases
parenthesis parentheses
phenomenon phenomena
seraph seraphim (or seraphs)
stratum strata
tableau tableaux
thesis theses

[19] "Foundations," pp. 47-48.


EXERCISE XIV.[20]

1. _Write the plural of_: Alumna, analysis, beau, cherub, crisis,
curriculum, genus, genius, hypothesis, nebula, oasis, parenthesis,
phenomenon, synopsis, seraph, stratum, tableau.
2. _Write the singular of_: Alumni, curricula, data, bacteria,
cherubim, oases, phenomena, seraphim, strata, theses.

GENDER.--The following nouns of different genders are sometimes