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:
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.