"Declinatio Octopus, Octopi in Quodam Libro"
"Inflection Octopus, Octopi in a Certain Book"
Rose Williams, a veteran Latin instructor, wrote a series of Latin-language books for the younger folks. One of them is this one:
Octavus Octopus: Octavus the Octopus Well, look how the word octopus is declined in the book:
![](http://i55.tinypic.com/2hztqnn.jpg)
It is second-declension and masculine. The nominative plural form is octopi, as seen in one of the choose-the-correct-answer section:
"The mother says, "Octopi have no [a. feet]."
Once again, so much for the idea that octopi is an error made by people ignorant of the Greek and Latin languages!