You may recall classical Linnean taxonomy with the mnemonic "Kings Play Chess On Funky Green Squares" (or one of the racier alternatives) or perhaps you simply committed it to memory: Kingdom, Phylum, Class, Order, Family, Genus, Species. But if you hear about a group of animals--cephalopods for example--how are you to know which level it belongs in? Rules are variable, as is the case in much of biology, but the best clue is the last few letters of the word.

Unfortunately that doesn't help with Cephalopoda, so I'll just go ahead and tell you that it's a class. Squid form their own order within this class:

Animalia
    Mollusca
        Cephalopoda
            Teuthoidea

and within this squid order, there are dozens of families:

                Ommastrephidae (flying squid)
                Cranchiidae (glass squid)
                Architeuthidae (giant squid)
                . . . and so on . . . 

I provide this information simply as background for a story: tonight I mentioned Squid-A-Day to one of my friends, and he thought I said Squididae.

And I thought that was the funniest, cleverest thing I'd ever heard.

And then I realized it was probably time to go to bed.