ot,
_maculae_; _minutia_, a little thing, _minutiae_; _nebula_, a mist, _nebulae_;
_siliqua_, a pod, _siliqiuae_. _Dogma_ makes _dogmas_ or _dogmata_;
_exanthema, exanthemas_ or _exanthemata_; _miasm_ or _miasma, miasms_ or
_miasmata_; _stigma, stigmas_ or _stigmata_.

2. Of nouns in _um_, some have no need of the plural; as, _bdellium,
decorum, elysium, equilibrium, guaiacum, laudanum, odium, opium, petroleum,
serum, viaticum_. Some form it regularly; as, _asylums, compendiums,
craniums, emporiums, encomiums, forums, frustums, lustrums, mausoleums,
museums, pendulums, nostrums, rostrums, residuums, vacuums_. Others take
either the English or the Latin plural; as, _desideratums_ or _desiderata,
mediums_ or _media, menstruums_ or _menstrua, memorandums_ or _memoranda,
spectrums_ or _spectra, speculums_ or _specula, stratums_ or _strata,
succedaneums_ or _succedanea, trapeziums_ or _trapezia, vinculums_ or
_vincula_. A few seem to have the Latin plural only: as, _arcanum, arcana;
datum, data; effluvium, effluvia; erratum, errata; scholium, scholia_.

3. Of nouns in _us_, a few have no plural; as, _asparagus, calamus, mucus_.
Some have only the Latin plural, which usually changes _us_ to _i_; as,
_alumnus, alumni; androgynus, androgyni; calculus, calculi; dracunculus,
dracunculi; echinus, echini; magus, magi_. But such as have properly become
English words, may form the plural regularly in _es_; as, _chorus,
choruses_: so, _apparatus, bolus, callus, circus, fetus, focus, fucus,
fungus, hiatus, ignoramus, impetus, incubus, isthmus, nautilus, nucleus,
prospectus, rebus, sinus, surplus_. Five of these make the Latin plural
like the singular; but the mere English scholar has no occasion to be told
which they are. _Radius_ makes the plural _radii_ or _radiuses_. _Genius_
has _genii_, for imaginary spirits, and _geniuses_, for men of wit.
_Genus_, a sort, becomes _genera_ in Latin, and _genuses_ in English.
_Denarius_ makes, in the plural, _denarii_ or _denariuses_.

4. Of nouns in _is_, some are regular; as, _trellis, trellises_: so,
_annolis, butteris, caddis, dervis, iris, marquis, metropolis, portcullis,
proboscis_. Some seem to have no need of the plural; as, _ambergris,
aqua-fortis, arthritis, brewis, crasis, elephantiasis, genesis, orris,
siriasis, tennis_. But most nouns of this ending follow the Greek or Latin
form, which simply changes _is_ to _=es_: as, _amanuensis, amanuenses;
analysis, analyses; antithesis, antithe