A firefly is not a fly – it is a beetle
A prairie dog is not a dog – it is a rodent [image above]
India ink is not from India – it is from China and Egypt
A horned toad is not a toad – it is a lizard
A lead pencil does not contain lead – it contains graphite
A douglas fir is not a fir – it is a pine [image above]
A silkworm is not a worm – it is a caterpillar
A peanut is not a nut – it is a legume
A koala bear is not a bear – it is a marsupial
An English horn is not English and it isn’t a horn – it is a French alto oboe
A guinea pig is not from guinea and it is not a pig – it is a rodent from South America
Shortbread is not a bread – it is a thick cookie [image above]
Dresden China is not from Dresden – it is from Meissen
A shooting star is not a star – it is a metorite
A funny bone is not a bone – it is the spot where the ulnar nerve touches the humerus
Chop suey is not a native Chinese dish – it was invented by Chinese immigrants in California
A bald eagle is not bald – it has flat white feathers on its head and neck when mature, and dark feathers when young [image above]
A banana tree is not a tree – it is a herb
A cucumber is not a vegetable – it is a fruit
A jackrabbit is not a rabbit – it is a hare
A piece of catgut is not from a cat – it is usually made from sheep intestines
A Mexican jumping bean is not a bean – it is a seed with a larva inside
A Turkish bath is not Turkish – it is Roman
A sweetbread is not a bread – it is the pancreas or thymus gland from a calf or lamb [image above] Source: The Book of Lists, 2