4. It's all Greek to me.

Greek and Latin words adopted into English

Many English words, especially in biology, medicine, and law, have been adopted from Latin or Greek. Although most English words form their plurals simply by adding the letter 's', this is not true of these words. Examples are listed below.



alumnus (male) alumni
cercus cerci
fungus fungi
ocellus ocelli
palpus  palpi
tarsus tarsi
alga algae
alumna (female) alumnae
antenna  antennae
coxa coxae
# exuviae
lamella lamellae
larva larvae
maxilla maxillae
pupa pupae
seta setae
tibia tibiae
agendum # # agenda
bacterium bacteria
cilium cilia
datum # # data
flagellum flagella
# # # genitalia
labium labia
medium media
labrum labra
ommatidium ommatidia
operculum opercula
ovum ova
sensillum sensilla
sternum sterna
tergum terga
tympanum  tympana
foramen foramina
corpus corpora
femur femora
genus genera
# # # faeces (feces)
axis axes
navis naves
penis penes
species  species



chrysalis  chrysalids or chrysalides
proboscis proboscides
criterion criteria
elytron elytra
ganglion ganglia
protozoon or protozoan* protozoa
phytotelma phytotelmata
stemma stemmata
stigma stigmata
stoma stomata

# does not exist in singular form

# # words agendum and datum are rarely used in English; agenda means "things to do," and is plural; there is no such word as "agendas" although such a word has been used in the popular press by ignorance, and although it may be listed in WWWebster's dictionary

# # # the singular is not used in English; feces is an American (not Latin) spelling

* protozoon is from Greek, but protozoan is English, formed from Protozoa

For additional words of this kind, see Nichols, S.W. 1989. The Torre-Bueno Glossary of Entomology. Revised Edition. New York Entomological Society; American Museum of Natural History, New York, NY. -- every professional entomologist should own a copy of this book.