After numerals, the singular form of such words as these is generally employed; as, five pair of gloves, eight couple of dancers, three brace of pigeons, five dozen of eggs, four score years, twenty sail of ships, fifty head of cattle, six hundred of these men, two thousand of these cattle, etc.
After such indefinite adjectives as few, many, several, some of the above words take the plural form; as, several hundreds, many thousands.
Index, Appendix
Indexes of books; indices, if applied to mathematical signs in algebra. Appendixes or appendices.
Fish, Fly
The plural of fish is fishes when considered individually, and fish when considered collectively. “My three pet fishes feed out of my hand.” “Six barrels of fish were landed from the schooner.”
Most words ending in y change this termination into ies, as duties, cities, etc. The plural of fly, the insect, is formed in the usual manner, but fly, a light carriage, adds s; as, “Six flys carried the guests to their homes.”
Animalcule
The plural of this word is animalcules. There is no plural animalculae. The plural of the Latin animalculum is animalcula.
Bandit